Welcome to appleseed-maya’s documentation!¶
Documentation generated on 2020-01-12 at 16:51
Contents¶
Features¶
appleseed-maya is an appleseed plugin for Autodesk® Maya®.
Main exporter features¶
Presently the exporter supports:
- Rendering to Maya’s RenderView
- Batch Rendering
- Appleseed project export (*.appleseed files) or packed appleseed project files (*.appleseedz)
- Image Based Lighting via appleseed Physical Sky, and Dome Light
- Support for most of Maya’s hypershade nodes (see Supported HyperShade Nodes)
- Several appleseed specific materials, texture, and utility nodes. See Custom appleseed shaders for detailed information
- Shader overrides with diagnostic modes, ambient occlusion geometric information
- Final render denoising [Boughida:2017:BCD:3128450.3128464]
- Support for custom OSL shaders as Maya shading nodes
- Support for OpenColorIO (or OCIO)
- Partial support [1] for Maya’s SynColor [2] color management system.
Limitations¶
Presently appleseed has the following limitations:
- Swatch rendering is limited to material nodes, not texture node
- IPR is not supported yet
- XGen support is work-in-progress and is disabled in this release
- Only meshes are exported and rendered right now
- PTex is not supported yet
- The rendering or working space is limited to Rec.709/sRGB RGB primaries with a D65 whitepoint
See also
appleseedhq GSoC 2018 wiki if you want to assist implementing any of these features.
Footnotes
| [1] | For now, the input device transforms supported for the ingested material are listed in asTexture Color Management options. |
| [2] | Maya’s native color management system, providing equivalent functionality to OpenColorIO. Not all input transformations are supported. See Autodesk Color Management Supplemental Information for more details. |
References
| [BB17] | Malik Boughida and Tamy Boubekeur. Bayesian collaborative denoising for monte carlo rendering. Comput. Graph. Forum, 36(4):137–153, jul 2017. URL: https://doi.org/10.1111/cgf.13231, doi:10.1111/cgf.13231. |
Installation¶
The plugin is a Maya module.
1. Uncompress the zip file.
2. Add the path containing the
appleseed-maya.modfile to yourMaya.env[1] file or to theMAYA_MODULE_PATHenvironment variable.3. Launch Maya and enable the plugin in the Plug-in Manager.
Footnotes
| [1] | See Setting environment variables using Maya.env. |
Supported HyperShade Nodes¶
Support status for the Hypershade nodes, and some extra plugin nodes. If the node support status is empty, it means that the node might or might not be supported at a later date.
Utilities¶
| Nodes | Support Status |
|---|---|
| Add Double Linear | Supported |
| Add Matrix | Supported |
| Angle Between | |
| Array Mapper | |
| Blend Colors | Supported |
| Blend Two Attr | |
| Bump2d | Supported |
| Bump3d | Supported |
| Choice | |
| Chooser | |
| Clamp | Supported |
| Clearcoat | Supported |
| Color Profile | Supported (WIP) |
| Compose Matrix | |
| Condition | Supported |
| Curve Info | |
| Decompose Matrix | |
| Distance Between | Supported |
| Double Switch | Supported (WIP) |
| Euler to Quat | |
| Four by Four Matrix | Supported |
| Frame Cache | Unsupported |
| Gamma Correct | Supported |
| Height Field | Unsupported |
| HSV to RGB | Supported |
| Inverse Matrix | Supported |
| Light Info | |
| Luminance | Supported |
| Mult Double Linear | Supported |
| Mult Matrix | Supported |
| Multiply Divide | Supported |
| Particle Sample | |
| 2D Placement | Supported |
| 3D Placement | Supported |
| Plus Minus Average | Supported |
| Projection | Unsupported [1] |
| Quad Switch | Supported (WIP) |
| quatNodes Add | |
| quatNodes Conjugate | |
| quatNodes Invert | |
| quatNodes Negate | |
| quatNodes Normalize | |
| quatNodes Prod | |
| quatNodes Sub | |
| quatNodes to Euler | |
| Remap Color | Supported |
| Remap HSV | Supported |
| Remap Value | Supported |
| Reverse | Supported |
| RGB to HSV | Supported |
| Sampler Info | Supported |
| SetRange | Supported |
| SingleSwitch | Supported (WIP) |
| Stencil | Supported |
| Surface Info | |
| Surf.Luminance | Unsupported |
| Transpose Matrix | Supported |
| Triple Switch | Supported (WIP) |
| Unit Conversion | |
| UV Chooser | |
| Vector Product | Supported |
| Weighted Add Matrix | Supported |
Footnotes
| [1] | An alternative to Maya’s projection node will come on the form of a custom appleseed shader. |
Surface¶
| Nodes | Support Status |
|---|---|
| GLSL Shader | Unsupported |
| ShaderFX shader | Unsupported |
| StingRayPBS | Unsupported |
| Anisotropic | Supported |
| Bifrost Aero | |
| Bifrost Foam | |
| Bifrost Liquid | |
| Blinn | Supported |
| CgFX Shader | Unsupported |
| Hair Tube Shader | |
| Lambert | Supported |
| Layered Shader | Unsupported [2] |
| Ocean Shader | |
| Phong | Supported |
| PhongE | Supported |
| Ramp Shader | |
| Shading Map | Unsupported |
| Surface Shader | |
| Use Background |
Footnotes
| [2] | An alternative appleseed node is provided, asBlendShader for the layering of shaders, and two shaders are provided to blend, and to composite textures. Namely asBlendColor and asCompositeColor. These provide functionality that greatly exceeds this node’s capabilities. |
Volumetric¶
| Nodes | Support Status |
|---|---|
| Env Fog | |
| Fluid Shape | |
| Light Fog | |
| Particle Cloud | |
| Volume Fog | |
| Volume Shader |
2D Textures¶
| Nodes | Support Status |
|---|---|
| Bulge | Supported |
| Checker | Supported |
| Cloth | Supported |
| File | Supported |
| Fluid Texture 2D | |
| Fractal | Supported |
| Grid | Supported |
| Mandelbrot | Supported [3] |
| Mountain | Supported |
| Movie | Supported [4] |
| Noise | Supported |
| Ocean | WIP |
| PSD File | Supported |
| Ramp | Supported |
| Substance | Supported [5] |
| Substance Output | Unsupported [6] |
| Water | Supported |
Footnotes
| [3] | The Mandelbrot2D node is partially supported only. |
| [4] | The Movie node requires OIIO built with FFMPEG. Reliable access to individual frames of a video file, or frame-by-frame scrubbing works as expected with I-frames only videos. |
| [5] | In order to use Substance materials, you need to use the Maya’s Substance node image file output. This will be covered on its own tutorial. |
| [6] | For now, The Substance Output is unsupported. This might change in the future. |
3D Textures¶
| Nodes | Support Status |
|---|---|
| Brownian | Supported |
| Cloud | Supported |
| Crater | Supported |
| Fluid Texture 3D | |
| Granite | Supported |
| Leather | WIP |
| Mandelbrot 3D | |
| Marble | Supported |
| Rock | Supported |
| Snow | Supported |
| Solid Fractal | Supported |
| Stucco | Supported |
| Volume Noise | Supported |
| Wood | Supported |
Environment Textures¶
| Nodes | Support Status |
|---|---|
| Env Ball | |
| Env Chrome | Supported |
| Env Cube | |
| Env Sky | |
| Env Sphere |
Lights¶
| Nodes | Support Status |
|---|---|
| Ambient Light | Unsupported |
| Area Light | Supported |
| Directional Light | Supported |
| Point Light | Supported |
| Spot Light | Supported |
| Volume Light |
asBlackbody¶
A blackbody radiator material [CGF:CGF1986] shader, with an optional glossy specular term on top, which also outputs the black body radiator color besides the output closure.
Parameters¶
Incandescence Parameters¶
- Incandescence Type
The type of color for the emitance distribution function, it can be
- Constant
- Blackbody
When in Blackbody mode it uses physically based values, that might have extremely high intensities as the temperature increases.
- Color
- The color to use when in Constant mode, ignored in Blackbody mode.
- Incandescence Amount
- The overall intensity of the incandescence, it can be over 1.0.
- Temperature Scale
- A scaling factor for the temperature value used to compute the black body radiation. Unlike incandescence amount, this actually affects the output color, with lower values generating warmer colors and lower energy levels, and higher values generating cooler values with higher energy levels.
- Temperature
- The temperature to which the perfect black body is heated to emit electro-magnetic radiation.
- Normalize Area
- When objects are deformed, their surface area might change. Without this option, the intensities would stay the same regardless of the deformation of the object to which the shader is attached. It this option enabled, the intensities will change taking into account the object surface area, in order to keep the amount of emitted energy constant.
- Tonemap Color
- As temperature increases, the black body radiator emits color in bluer wavelenghts, but the amount of energy emitted is extreme. In order to avoid extremely hight intensities, this option allows the user to tonemap the resulting black body color.
Specular Parameters¶
- Specular Amount
- The intensity of the specular term.
- Specular Roughness
- The apparent surface roughness of the specular term.
- Index of Refraction
- Absolute index of refraction
Note
This term is a simple dielectric specular term using the GGX [heitz:hal-00996995] microfacet distribution function, with energy compensation for high roughness values.
Bump Parameters¶
- Bump Normal
- The unit length world space normal of the bumped surface.
Matte Opacity Parameters¶
- Enable Matte Opacity
- Parameter that toggles matte holdouts.
- Matte Opacity
- Matte opacity scaling factor.
- Matte Opacity Color
- Holdout color.
Advanced Parameters¶
- Ray Depth
- The maximum ray depth a ray is allowed to bounce before being terminated.
Outputs¶
- Output Color
- The combined EDF+BRDF output color.
- Output Matte Opacity
- The matte holdout.
- Output Blackbody Color
- The black body radiator color.
Screenshots¶
References
| [HDEon14] | Eric Heitz and Eugene D’Eon. Importance Sampling Microfacet-Based BSDFs using the Distribution of Visible Normals. Computer Graphics Forum, 33(4):103–112, July 2014. URL: https://hal.inria.fr/hal-00996995, doi:10.1111/cgf.12417. |
| [WW11] | A. Wilkie and A. Weidlich. A physically plausible model for light emission from glowing solid objects. Computer Graphics Forum, 30(4):1269–1276, 2011. URL: http://dx.doi.org/10.1111/j.1467-8659.2011.01986.x, doi:10.1111/j.1467-8659.2011.01986.x. |
asBlendShader¶
A shader node allowing the user to blend up to 8 BxDFs [1]. Unlike with physically correct BxDF stacks or layers [Jakob:2014:CFR:2601097.2601139] , this node just blends the inputs according to the input mixing weights. There is no interaction in terms of light transport between the top and bottom shaders.
Parameters¶
Blend Parameters¶
- Layer 0
- The first layer shader, from bottom to top order, with layer 0 at the bottom, and layer 7 at the top.
- Layer 0 Weight
- The first layer weight. [2]
- Layer 0 Visibility
- A flag that toggles the respective layer contribution on or off.
(…)
Note
The subsequent layers follow exactly the same structure and parameterization.
- Layer 7
- The last layer shader, the layer at the top.
- Layer 7 Weight
- The last layer weight.
- Layer 7 Visibility
- The last layer visibility flag. Toggling the contribution of this layer on or off.
Warning
This node does not layer colors, that is, it is meant to layer BxDF, EDF or other closures, not ordinary colors. Without a valid connection [3] to the input, nothing will be layered in the respective layer.
Screenshots¶
Footnotes
| [1] | See BSDF definition. |
| [2] | The layering weight on the first layer, Layer 0, will make a blend between 0 (black), and the Layer 0 Color. |
| [3] | A valid connection would be any closure, so any material shader, such as Maya’s Blinn, or appleseed’s asSubsurface, asMetal, just to name a few. Color nodes such as Noise2D, simple selected colors, and so on, are not valid choices. To blend or composite colors, use the asBlendColor or asCompositeColor nodes instead. |
References
| [JdEonJM14] | Wenzel Jakob, Eugene d’Eon, Otto Jakob, and Steve Marschner. A comprehensive framework for rendering layered materials. ACM Trans. Graph., 33(4):118:1–118:14, jul 2014. URL: http://doi.acm.org/10.1145/2601097.2601139, doi:10.1145/2601097.2601139. |
asDisneyMaterial¶
The Disney principled BRDF [McAuley:2012:PPS:2343483.2343493], a physically based material.
Parameters¶
Common Material Parameters¶
- Surface Color
- The surface color
- Subsurface Amount
- The amount of sub-surface scattering [1]
Specular Parameters¶
- Specular Amount
- The amount of specular highlights
- Specular Roughness
- The apparent surface roughness affecting the specular highlights
- Specular Tint
- The tinting amount of the specular highlights, with a value 0 having achromatic highlights, and a value of 1.0 inheriting the surface color.
- Metallicness
- A low value is suitable for the appearance of dielectrics such as plastic, with a higher value producing more intensity specular reflections, and more suitable for conductors.
- Anisotropy Amount
- The amount of anisotropy affecting the specular highlights, with a value of 0.0 producing isotropic highlights, and a value of 1.0 producing full anisotropic highlights.
- Anisotropy Angle
- The angle affecting anisotropic highlights, which maps the values from [0,1] range into [0,360] range.
- Anisotropy Vector Map
- A vector tangent field (color) map, with the X and Y anisotropy directions encoded in the R and G channels.
Sheen Parameters¶
- Sheen Amount
- The amount of sheen, see Westin velvet.
- Sheen Tint
- The tinting (color) affecting the sheen effect.
Coating Parameters¶
- Coating Amount
- The amount of (clear) coating on the material, producing an extra layer of (usually) sharp highlights.
- Coating Glossyness
- The coating layer glossyness, with low values producing a dull like highlight, similar to a high surface roughness value, and higher values producing sharper highlights.
Bump Parameters¶
- Bump Normal
- The unit length (bump) normal, usually passed from a bump2d or a bump3d node.
Advanced Parameters¶
- Ray Depth
- The maximum number of bounces a ray is allowed to travel.
Outputs¶
- Output Color
- The final result color.
- Output Transparency
- The resulting transparency (unused presently).
- Output Matte Opacity
- The resulting matte opacity.
Screenshots¶
Footnotes
| [1] | In the shader, it’s not a full BSSRDF, but an approximation using only single scattering. |
References
| [MHH+12] | Stephen McAuley, Stephen Hill, Naty Hoffman, Yoshiharu Gotanda, Brian Smits, Brent Burley, and Adam Martinez. Practical physically-based shading in film and game production. In ACM SIGGRAPH 2012 Courses, SIGGRAPH ‘12, 10:1–10:7. New York, NY, USA, 2012. ACM. URL: http://doi.acm.org/10.1145/2343483.2343493, doi:10.1145/2343483.2343493. |
asGlass¶
A Glass BSDF [Walter2007], with volumetric absorption.
Parameters¶
Surface Transmittance¶
- Transmittance Color
- The color that is transmitted to the underlying glass medium. A color of 0 will mean no transmittance will take place, a color of one will mean full transmittance. This parameter is weighted by the next parameter, transmittance amount.
- Transmittance Amount
- Transmittance amount, with a value of 0 meaning no light reaches the glass medium, and a value of 1.0 meaning a full amount reaching the glass medium. This is useful for compositing the glass BSDF with other BxDFs.
Specular Parameters¶
- Reflection Tint
- Overall tint for the reflection (BRDF) component of the glass BSDF.
- Refraction Tint
- Overall tint for the refraction (BTDF) component of the glass BSDF.
- Index of Refraction
- Absolute index of refraction
- Roughness
- The apparent surface roughness, affecting both the reflection and refraction equally.
- Anisotropy Amount
- Overall intensity of the anisotropy effect, with a value of 0.0 representing isotropic specular highlights.
- Anisotropy Angle
- Rotation angle for the anisotropic highlights, with the value in [0,1] range mapping to a rotation from 0 to 360 degrees.
- Anisotropy Vector Map
- Also known as tangent field, encodes the anisotropy directions along X and Y in the Red and Green or Red and Blue channels of the image. appleseed expects values encoded in the Red and Green channels.
Volume Material Parameters¶
- Volume Transmittance
- Color of the volumetric absorption as the refracted ray travels within the medium.
- Transmittance Distance
- The distance at which full absorption is supposed to occur. When this distance is set to 0, no absorption takes place. Lower values imply a stronger absorption, and higher values imply a weaker absorption effect as the ray would need to travel a greater distance for full absorption to take place.
Bump Parameters¶
- Bump Normal
- The unit length world space normal of the bumped surface.
Advanced Parameters¶
- Ray Depth
- The maximum ray depth a ray is allowed to bounce before being terminated.
Outputs¶
- Output Color
- The BSDF output color.
- Output Transparency
- The output transparency.
Note
The output transparency is unused at the moment.
Screenshots¶
References
| [WMLT07] | Bruce Walter, Stephen R. Marschner, Hongsong Li, and Kenneth E. Torrance. Microfacet models for refraction through rough surfaces. In Proceedings of the 18th Eurographics Conference on Rendering Techniques, EGSR‘07, 195–206. Aire-la-Ville, Switzerland, Switzerland, 2007. Eurographics Association. URL: http://dx.doi.org/10.2312/EGWR/EGSR07/195-206, doi:10.2312/EGWR/EGSR07/195-206. |
asMatte¶
A matte holdout shader allowing the user to specify an arbitrary color and matte opacity.
Parameters¶
Surface Parameters¶
- Color
- The input material to pass-through for non-camera rays.
Note
Most materials have their own matte controls, however the user might wish to blend materials, with for instance, the asBlendShader node, and for such it might be preferable to set this matte node at the root of the shader graph.
Matte Parameters¶
- Enable Matte
- Checkbox that toggles matte holdouts on or off.
- Matte Color
- The color for the matte, only visible for camera rays.
- Matte Opacity
- The opacity value written to the alpha channel.
asMetal¶
A metal shader, with anisotropy and a user-friendly [Gulbrandsen2014Fresnel] complex index of refraction Fresnel, with some presets for common metal types derived from real-world measurements [1].
Parameters¶
Fresnel Parameters¶
- Face Reflectance
- RGB reflectance at normal or facing incidence.
- Edge Reflectance
- RGB reflectance at edge or grazing incidence.
Specular Parameters¶
- Roughness
- The apparent surface roughness.
- Energy Compensation
Microfacet models typically fail to take into account multiple scattering [Heitz:2016:MMB:2897824.2925943], and as such, with high roughness values there is a substancial energy loss. To what extent it depends mostly on the MDF used, with GGX exhibiting considerable energy loss.
In order to negate the impact of this energy loss a separate compensation term is applied. This parameter scales the contribution of this compensation term, with a value of 1.0 trying to compensate for all the energy lost, and a value of 0.0 essentially disabling any compensation.
See also
This is covered in SIGGRAPH 2017 physically based shading course Revisiting Physically Based Shading at Imageworks (Christopher Kulla and Alejandro Conty).
Anisotropy¶
- Anisotropy Amount
- Overall intensity of the anisotropy effect, with a value of 0.0 representing a isotropic specular highlight.
- Anisotropy Angle
- Rotation angle for the anisotropic highlight in [0,1], mapping a rotation from 0 to 360 degrees.
- Anisotropy Mode
Toggles between accepting a direct texture map in the form of an anisotropy vector map, or between an explicit vector (or a connection to a node that generates such a vector [2] ). It can take the values
- Anisotropy Map
- Explicit Vector
- Anisotropy Map
- Also known as tangent field, encodes the anisotropy directions along X and Y in the Red and Green or Red and Blue channels of the image. Appleseed expects values encoded in the Red and Green channels. Valid when the Anisotropy Mode is set to Anisotropy Map only.
- Anisotropy Direction
- The explicit vector passed as the anisotropy direction. Valid when the Anisotropy Mode is set to Explicit Vector only.
Bump Parameters¶
- Bump Normal
- The unit length world space normal of the bumped surface.
Matte Opacity Parameters¶
- Enable Matte Opacity
- Parameter that toggles matte holdouts.
- Matte Opacity
- Matte opacity scaling factor.
- Matte Opacity Color
- Holdout color.
Advanced Parameters¶
- Ray Depth
- The maximum ray depth a ray is allowed to bounce before being terminated.
Screenshots¶
Footnotes
| [1] | From .nk files, containing the data for several metals, alloys, semi-conductors in several wavelenght ranges (not exclusively in the visible light range). Maya attribute presets are provided for aluminium, brass, chromium, copper, gold, iron, lead, mercury, nickel, osmium, platinum, aluminium-gold intermetallic (purple plague), silver, titanium, titanium nitride, tungsten and zinc. See the LuxPop database and refractive index database for more measured complex ior data. |
| [2] | Such as the anisotropy vector field node. |
References
| [Gul14] | Ole Gulbrandsen. Artist friendly metallic fresnel. Journal of Computer Graphics Techniques (JCGT), 3(4):64–72, December 2014. URL: http://jcgt.org/published/0003/04/03/. |
| [HHdEonD16] | Eric Heitz, Johannes Hanika, Eugene d’Eon, and Carsten Dachsbacher. Multiple-scattering microfacet bsdfs with the smith model. ACM Trans. Graph., 35(4):58:1–58:14, jul 2016. URL: http://doi.acm.org/10.1145/2897824.2925943, doi:10.1145/2897824.2925943. |
asPlastic¶
A physically correct plastic shader, stacking a specular term on top of a diffuse substrate.
Parameters¶
Diffuse Parameters¶
- Diffuse Color
- The diffuse color.
- Diffuse Weight
- A scaling factor for the diffuse BRDF.
- Scattering
- The scattering amount for the diffuse term. Full scattering will take into account all the events in the specular term, while a value of 0 will disable them.
Specular Parameters¶
- Specular Color
- The specular color.
- Specular Weight
- A scaling factor for the specular BRDF.
- Index of Refraction
- The index of refraction for the (dielectric [1]) Fresnel term.
- Specular Roughness
- The apparent surface roughness, with a value near 0 producing sharp highlights, and a value of 1.0 producing soft diffuse like highlights.
Note
As specular roughness values increase, there is energy loss due to the lack of multiple scattering [Heitz:2016:MMB:2897824.2925943]. Appleseed however does compensate for this energy loss.
Bump Parameters¶
- Bump Normal
- The unit length world space normal of the bumped surface.
Matte Opacity Parameters¶
- Enable Matte Opacity
- Parameter that toggles matte holdouts.
- Matte Opacity
- Matte opacity scaling factor.
- Matte Opacity Color
- Holdout color.
Advanced Parameters¶
- Ray Depth
- The maximum ray depth a ray is allowed to bounce before being terminated.
Screenshots¶
Footnotes
| [1] | Dielectric is a material which is an electric insulator, the opposite of conductors which as the name says, conducts electricity. See this page on dielectric materials for more details. In terms of look development an accepted simplification is that dielectrics have white or non-tinted specular highlights, while conductors have tinted or coloured specular highlights. |
| [2] | The microfacet distribution function is a function that describes statistically the microscopic shape of the surface’s as a distribution of microfacet orientations. See the this page on the normal distribution function (NDF), and this page on specular highlights for more details. |
References
| [HHdEonD16] | Eric Heitz, Johannes Hanika, Eugene d’Eon, and Carsten Dachsbacher. Multiple-scattering microfacet bsdfs with the smith model. ACM Trans. Graph., 35(4):58:1–58:14, jul 2016. URL: http://doi.acm.org/10.1145/2897824.2925943, doi:10.1145/2897824.2925943. |
asSbsPBRMaterial¶
A shader created to give a good visual match with Allegorithmic Substance Painter’s PBR material (roughness based workflow). It also has dedicated input slots for many of Substance Painter’s exported auxiliary textures. For convenience the parameters were labelled and grouped as much as possible matching the conventions used in Substance Painter.
See also
Parameters¶
Ambient Occlusion¶
- Ambient Occlusion
- This parameter does not compute any ambient occlusion itself. Rather it expects the exported ambient occlusion auxiliary texture from Substance Painter if such channel was exported (which is usually exported with scene-linear encoding).
Surface Color¶
- Base Color
- The surface color channel, which usually is set by default to use the sRGB OETF [1].
See also
See The importance of terminology and sRGB uncertainty for more details.
Emissive¶
- Emissive Color
- The color to use for the incandescence effect, usually encoded with a sRGB OETF by default.
- Emissive Intensity
- A scaling factor for the incandescence effect.
Height¶
- Height
- The value to use for scalar bump mapping, usually a grayscale texture (and raw quantity).
- Scale
- An overall scaling factor for the scalar bump mapping quantity height.
Metallic¶
- Metallic
- The metallicness or metallic texture slot. With low values the specular appearance is that of a dielectric such as plastic or glass, while higher values produce the appearance of metal.
Normal¶
- Normal
- The slot for normal mapping. In Maya this automatically creates a bump2d node whose bump mode must be set to tangent space bump mapping. With other DCC applications, you should create a asBump node instead, and set its mode parameters to Normal Map while having in mind that exporting a map in OpenGL or DirectX convention will flip the G channel of the exported map of one in regard to the other. See the asBump documentation for more details.
Roughness¶
- Roughness
- The roughness texture channel. A raw quantity usually exported as a grayscale texture.
Opacity¶
- Opacity
- The opacity texture channel, with a value of 0.0 denoting a fully transparent surface, and a value of 1.0 denoting a fully opaque surface. A raw quantity usually exported as a grayscale texture.
Specular¶
- Specular Level
- The slot for the specular level texture. By default this quantity is not usually exposed to the user and is set to a fixed value.
Note
The Specular Level is not exposed by default, but it can be exposed. Its default value of 0.5 will be scaled internally and used to determine the reflectance at facing or normal incidence. This in turn will drive the Fresnel reflectance which is used to control the appearance of the dielectric specular term.
Anisotropy¶
- Anisotropy Level
- The slot for the amount of anisotropy for the specular highlights, if the user created and exported such a channel. A raw quantity usually saved as a grayscale texture.
- Anisotropy Angle
- The slot or value for an anisotropy rotation angle, where the value 1.0 maps to 360 degrees rotation. A raw quantity usually saved as a grayscale texture.
Refraction¶
- Refraction
- The amount of refraction, where a value of 0 is a diffuse BRDF [2], and a value of 1 is a pure smooth specular BTDF [3], and in-between values blending between the diffuse and refractive term.
- Refraction IOR
- The index of refraction [4] of the material. This parameter affects only the refraction term and has no effect whatsoever on the specular term.
- Scattering
- Controls how much light is scattered through the surface. Unused at the moment.
- Absorption
- Controls how much light is absorbed through the surface, with a value of 1.0 leading to the light being fully absorbed by the medium.
- Absorption Color
- Controls how light shifts when light traverses the medium’s volume.
Matte Parameters¶
- Enable Matte
- Flag toggling matte holdouts on or off.
- Matte Opacity
- Overall scaling factor for the matte, from solid black to normal.
- Matte Opacity Color
- Color for the matte.
Advanced Parameters¶
- Maximum Ray Depth
- The maximum number of bounces a ray is allowed to travel.
Outputs¶
- Output Color
- The final result color.
- Output Transparency
- The final transparency color.
- Output Matte Opacity
- The final matte opacity. Note that OSL holdout is unsupported at the moment.
Notes¶
Attention
When using texture atlas such as UDIMs, have in mind that you’re probably going to have a large number of channels and textures to access. This will have a cost in performance. One way to maximize performance and mitigate this cost is to pre-process the textures with OpenImageIO’s maketx utility.
Screenshots¶
Footnotes
| [1] | By default, the color channel, and other color quantities are set to be encoded with the sRGB OETF. But note that you cannot specify RGB primaries or white point in Substance Painter, so you should assume these to be the sRGB/Rec.709 RGB primaries and D65 whitepoint if you intend to convert to other color spaces. |
| [2] | Which in this case is the Lambert BRDF. |
| [3] | See also the definition of BSDF for more details. |
| [4] | The real and absolute index of refraction of the material. Since dielectrics have a very small extinction coefficient, this is assumed to be 0, and monochromatic. Absolute since it’s assumed to be the ratio of the wave speed in the vacuum and wave speed in the medium. Appleseed is not querying the exterior medium with nested dielectrics [ND.2002.10487555] to compute the correct index of refraction. The priority was given to have as much as possible a matching appearance with Substance Painter’s PBR material. |
References
| [SB02] | Charles M. Schmidt and Brian Budge. Simple nested dielectrics in ray traced images. Journal of Graphics Tools, 7(2):1–8, 2002. URL: https://doi.org/10.1080/10867651.2002.10487555, arXiv:https://doi.org/10.1080/10867651.2002.10487555, doi:10.1080/10867651.2002.10487555. |
asStandardSurface¶
A physically based material with a dielectric coating with absorption, and a substrate with optional subsurface scattering, refraction, volumetric absorption.
Parameters¶
Diffuse Parameters¶
- Diffuse Weight
- A scaling factor for the diffuse BRDF.
- Diffuse Color
- The surface color.
- Diffuse Roughness
- The diffuse roughness, with a value of 0, it corresponds to a Lambert diffuse term. Higher values flatten the appearance of the surface, giving it a chalky look. [1]
Subsurface Parameters¶
- Subsurface Weight
- A weighting factor for the subsurface scattering term.
- Subsurface Mean Free Path (MFP)
- Color controling how far light enters and travels within the medium.
- Subsurface MFP Scale
- Overall scaling factor for the MFP color, which is expected in [0,1] range. Values above 1.0 are possible, resulting in increased translucency appearance.
Advanced¶
- Subsurface Profile
The diffusion profiles to use in the BSSDRF [2]. This parameter can take the following values:
- Gaussian [dEon:2007:ERH:2383847.2383869]
- Better Dipole
- Normalized Diffusion [Christensen:2015:ARP:2775280.2792555]
- Random Walk [Meng:2016:IDS:3071773.3071778]
Translucency Parameters¶
- Translucency Weight
- Controls the amount of thin translucency of the object.
- Translucency Color
- Color affecting the thin translucency term.
Specular Parameters¶
- Specular Color
- Overall specular tint for the specular BRDF.
- Specular Roughness
- The apparent surface roughness affecting the specular highlights.
Fresnel¶
- Fresnel Type
Allows the user to choose the specular mode, of a dielectric such as plastic or glass, or of a conductor or metal.
Note
To use refraction, the mode must be set to dielectric and the index of refraction set. When in conductor mode, the face tint and edge tint parameters are used to derive the complex index of refraction instead [Gulbrandsen2014Fresnel] and no refraction is used.
- IOR
- The index of refraction for the dielectric mode.
- Facing Tint
- The reflectance at normal incidence.
- Edge Tint
- Reflectance at grazing incidence.
Anisotropy¶
- Anisotropy Amount
- Overall intensity of the anisotropy effect, with a value of 0.0 representing a isotropic specular highlight.
- Anisotropy Angle
- Rotation angle for the anisotropic highlight in [0,1], mapping a rotation from 0 to 360 degrees.
- Anisotropy Map
- Also known as tangent field, encodes the anisotropy directions along X and Y in the Red and Green or Red and Blue channels of the image. Appleseed expects values encoded in the Red and Green channels.
Refraction Parameters¶
- Refraction Amount
- Intensity of the refraction, only taking place when Fresnel is dielectric [Walter2007].
- Refraction Tint
- Overall tinting factor, it affects the BTDF equally, unlike volumetric absorption.
Volumetric Absorption¶
- Absorption Depth
- Sets the depth at which full absorption takes place. Low values result in dense absorbing materials, high values in transparent appearance ones.
- Absorption Color
- The color used for the volumetric absorption.
Coating Parameters¶
- Coating Reflectivity
- Intensity of specular highlights on the coating.
- Coating Roughness
- Apparent surface roughness of the coating specular highlights.
- Coating IOR
- Index of refraction of the coating layer, usually a dielectric, with values around 1.5.
Coating Absorption¶
- Coating Thickness
- Thickness of the coating layer, controlling the intensity of coating absorption, with 0 being no absorption, 1 being full absorption.
- Coating Absorption
- Absorption color for the coating, white has no effect, black absorbs fully.
Incandescence Parameters¶
- Incandescence Amount
- The overall intensity of the incandescence effect.
- Incandescence Type
- Color choice for incandescence color, with constant taking as input the user-set value, and blackbody using a blackbody radiator. [3]
- Incandescence Color
- Incandescence color, ignored in blackbody mode.
- Temperature
- Temperature in Kelvin degrees, ignored in constant mode.
Options¶
- Area Normalize EDF
- Normalize by the object area, so that object deformations keep the incandescence energy. If unset, deforming the object will retain the incandescence color.
- Tonemap EDF
- Tonemaps the potentially high energy result of the blackbody radiator into the [0,1] range. Disabled by default.
Note
The tonemap EDF option has effect only when incandescence type is set to blackbody.
Transparency Parameters¶
- Transparency
- Affects the presence of an object. When transparency is binary (full opaque or full transparent, with no in-between values), appleseed alpha masks should be used instead.
Bump Parameters¶
- Coating Normal
- The bump normal for the coating layer.
- Substrate Normal
- The bump normal for the substrate.
Matte Parameters¶
- Enable Matte
- Flag toggling matte holdouts on or off.
- Matte Opacity
- Overall scaling factor for the matte, from solid black to normal.
- Matte Opacity Color
- Color for the matte.
Advanced Parameters¶
- SSS Ray Depth
- Maximum number of ray bounces for the subsurface scattering term.
- SSS Threshold
- Defines the distance light has to travel within the medium to start the subsurface scattering effect. A low enough mean free path value will have a visually negligible difference from a diffuse term. This parameter sets the threshold at which the subsurface calculations start, instead of the ordinary diffuse term.
- Maximum Ray Depth
- The maximum number of bounces a ray is allowed to travel.
Outputs¶
- Output Color
- The final result color.
- Output Transparency
- The final transparency color.
- Output Matte Opacity
- The final matte opacity. Note that OSL holdout is unsupported at the moment.
Screenshots¶
Footnotes
| [1] | The diffuse BRDF used is the Oren-Nayar BRDF [Oren:1994:GLR:192161.192213] |
| [2] | See also Extending the Disney BRDF to a BSDF with Integrated Subsurface Scattering for details. |
| [3] | https://en.wikipedia.org/wiki/Black-body_radiation |
References
| [Chr15] | Per H. Christensen. An approximate reflectance profile for efficient subsurface scattering. In ACM SIGGRAPH 2015 Talks, SIGGRAPH ‘15, 25:1–25:1. New York, NY, USA, 2015. ACM. URL: http://doi.acm.org/10.1145/2775280.2792555, doi:10.1145/2775280.2792555. |
| [dEonLE07] | Eugene d’Eon, David Luebke, and Eric Enderton. Efficient rendering of human skin. In Proceedings of the 18th Eurographics Conference on Rendering Techniques, EGSR‘07, 147–157. Aire-la-Ville, Switzerland, Switzerland, 2007. Eurographics Association. URL: http://dx.doi.org/10.2312/EGWR/EGSR07/147-157, doi:10.2312/EGWR/EGSR07/147-157. |
| [Gul14] | Ole Gulbrandsen. Artist friendly metallic fresnel. Journal of Computer Graphics Techniques (JCGT), 3(4):64–72, December 2014. URL: http://jcgt.org/published/0003/04/03/. |
| [MHD16] | Johannes Meng, Johannes Hanika, and Carsten Dachsbacher. Improving the dwivedi sampling scheme. Comput. Graph. Forum, 35(4):37–44, jul 2016. URL: https://doi.org/10.1111/cgf.12947, doi:10.1111/cgf.12947. |
| [ON94] | Michael Oren and Shree K. Nayar. Generalization of lambert’s reflectance model. In Proceedings of the 21st Annual Conference on Computer Graphics and Interactive Techniques, SIGGRAPH ‘94, 239–246. New York, NY, USA, 1994. ACM. URL: http://doi.acm.org/10.1145/192161.192213, doi:10.1145/192161.192213. |
| [WMLT07] | Bruce Walter, Stephen R. Marschner, Hongsong Li, and Kenneth E. Torrance. Microfacet models for refraction through rough surfaces. In Proceedings of the 18th Eurographics Conference on Rendering Techniques, EGSR‘07, 195–206. Aire-la-Ville, Switzerland, Switzerland, 2007. Eurographics Association. URL: http://dx.doi.org/10.2312/EGWR/EGSR07/195-206, doi:10.2312/EGWR/EGSR07/195-206. |
asSubsurface¶
A raytraced, no precomputed required, subsurface-scattering material with a coupled specular term. This node capable of modelling a wide range of appearance thanks to built-in support for several diffusion profiles.
Parameters¶
Subsurface Parameters¶
- Subsurface Profile
The diffusion profiles to use in the BSSDRF [1]. This parameter can take the following values
- Better Dipole
- Directional Dipole [Frisvad:2014:DDM:2702692.2682629]
- Gaussian [dEon:2007:ERH:2383847.2383869] [dEon:2011:QMR:1964921.1964951]
- Normalized Diffusion [Christensen:2015:ARP:2775280.2792555]
- Standard Dipole [Jensen:2001:PMS:383259.383319], [Donner:2005:LDM:1186822.1073308]
- Random Walk [Meng:2016:IDS:3071773.3071778]
- Reflectance
- The surface reflectance.
- SSS Amount
- A scaling factor for the overall contribution of the subsurface scattering term.
- Mean Free Path
- Mean free path [2] controls how deep light can travel within the volume, scattering internally, until it’s fully absorbed or exits the medium. Lower values in the limit would have a response similar to a diffuse term, while high values would allow light to travel almost unhindered, producing a translucent like appearance.
- MFP Scale
- An overall scaling factor for the Mean Free Path.
SSS Advanced Parameters¶
- SSS Ray Depth
- The maximum ray depth allowed for a ray of type subsurface.
Fresnel Parameters¶
- Index of Refraction
- The index of refraction of the material.
Fresnel Advanced Parameters¶
- Fresnel Weight
- A value of 1.0, will scale the subsurface contribution by the Fresnel transmittance, while a value of 0.0 will disable any scaling. When using the provided specular BRDF, in order to keep energy conservation, this scaling factor should be set to 1.0. If you’re not using the provided specular term and/or want to compose one later in your workflow, you can disable this. You also have the freedom to use intermediary values.
Specular Parameters¶
- Specular Weight
- An overall scaling factor for the specular term. A value of 1.0 provides full intensity, 0.0 disabling it.
Note
This shader allows the user to texture map the specular weight, to control the specular term intensity, but it does not provide a way to tint or color the specular term. That is intentional sually only dielectrics [3] have subsurface scattering, and dielectrics have no tinted specular highlights.
- Specular Roughness
- The apparent surface roughness of the material. The distribution used is the GGX [Walter2007], and energy conservation to take into account multiple scattering [Heitz:2016:MMB:2897824.2925943] is applied automatically.
Anisotropy Parameters¶
- Anisotropy Amount
- The overall weight of the anisotropy, with a value of 0.0 producing isotropic specular highlights, and a value of 1.0 producing full anisotropic specular highlights.
- Anisotropy Angle
- A rotation angle in [0,1] range, that is mapped internally to a full 360 degrees rotation and applied on top of the anisotropy value provided by the explicit anisotropy vector or anisotropy vector map.
- Anisotropy Mode
The anisotropy mode, which can either be a anisotropy vector map with the XY anisotropy encoded in the red and green channels of the image, or an explicit anisotropy vector, which can be provided via a asAnisotropyVectorField node. It can therefore take the values
- Anisotropy Map
- Explicit Vector
- Anisotropy Map
- The anisotropy vector map to use when Anisotropy Mode is set to Anisotropy Map.
- Anisotropy Direction
- An explicit anisotropy vector to use when the Anisotropy Mode parameter is set to Explicit Vector.
Bump¶
- Bump Normal
- The unit length world space normal of the bumped surface.
Matte Opacity¶
- Enable Matte Opacity
- Parameter that toggles matte holdouts.
- Matte Opacity
- Matte opacity scaling factor.
- Matte Opacity Color
- Holdout color.
Outputs¶
- Output Color
- The BSSRDF output with the optional added specular BRDF.
- Output Matte Opacity
- The matte holdout.
Screenshots¶
Footnotes
| [1] | See also bidirectional scattering distribution function. |
| [2] | See mean free path wikipedia page for more details. |
| [3] | Dielectric is a material which is an electric insulator, the opposite of conductors which as the name says, conducts electricity. See this page on dielectric materials for more details. In terms of look development an accepted simplification is that dielectrics have white or non-tinted specular highlights, while conductors have tinted or coloured specular highlights. |
References
| [Chr15] | Per H. Christensen. An approximate reflectance profile for efficient subsurface scattering. In ACM SIGGRAPH 2015 Talks, SIGGRAPH ‘15, 25:1–25:1. New York, NY, USA, 2015. ACM. URL: http://doi.acm.org/10.1145/2775280.2792555, doi:10.1145/2775280.2792555. |
| [DEonI11] | Eugene D’Eon and Geoffrey Irving. A quantized-diffusion model for rendering translucent materials. In ACM SIGGRAPH 2011 Papers, SIGGRAPH ‘11, 56:1–56:14. New York, NY, USA, 2011. ACM. URL: http://doi.acm.org/10.1145/1964921.1964951, doi:10.1145/1964921.1964951. |
| [dEonLE07] | Eugene d’Eon, David Luebke, and Eric Enderton. Efficient rendering of human skin. In Proceedings of the 18th Eurographics Conference on Rendering Techniques, EGSR‘07, 147–157. Aire-la-Ville, Switzerland, Switzerland, 2007. Eurographics Association. URL: http://dx.doi.org/10.2312/EGWR/EGSR07/147-157, doi:10.2312/EGWR/EGSR07/147-157. |
| [DJ05] | Craig Donner and Henrik Wann Jensen. Light diffusion in multi-layered translucent materials. In ACM SIGGRAPH 2005 Papers, SIGGRAPH ‘05, 1032–1039. New York, NY, USA, 2005. ACM. URL: http://doi.acm.org/10.1145/1186822.1073308, doi:10.1145/1186822.1073308. |
| [FHK14] | Jeppe Revall Frisvad, Toshiya Hachisuka, and Thomas Kim Kjeldsen. Directional dipole model for subsurface scattering. ACM Trans. Graph., 34(1):5:1–5:12, December 2014. URL: http://doi.acm.org/10.1145/2682629, doi:10.1145/2682629. |
| [HHdEonD16] | Eric Heitz, Johannes Hanika, Eugene d’Eon, and Carsten Dachsbacher. Multiple-scattering microfacet bsdfs with the smith model. ACM Trans. Graph., 35(4):58:1–58:14, jul 2016. URL: http://doi.acm.org/10.1145/2897824.2925943, doi:10.1145/2897824.2925943. |
| [JMLH01] | Henrik Wann Jensen, Stephen R. Marschner, Marc Levoy, and Pat Hanrahan. A practical model for subsurface light transport. In Proceedings of the 28th Annual Conference on Computer Graphics and Interactive Techniques, SIGGRAPH ‘01, 511–518. New York, NY, USA, 2001. ACM. URL: http://doi.acm.org/10.1145/383259.383319, doi:10.1145/383259.383319. |
| [MHD16] | Johannes Meng, Johannes Hanika, and Carsten Dachsbacher. Improving the dwivedi sampling scheme. Comput. Graph. Forum, 35(4):37–44, jul 2016. URL: https://doi.org/10.1111/cgf.12947, doi:10.1111/cgf.12947. |
| [WMLT07] | Bruce Walter, Stephen R. Marschner, Hongsong Li, and Kenneth E. Torrance. Microfacet models for refraction through rough surfaces. In Proceedings of the 18th Eurographics Conference on Rendering Techniques, EGSR‘07, 195–206. Aire-la-Ville, Switzerland, Switzerland, 2007. Eurographics Association. URL: http://dx.doi.org/10.2312/EGWR/EGSR07/195-206, doi:10.2312/EGWR/EGSR07/195-206. |
asSwitchSurface¶
A node that switches the output material from a list of 8 inputs, based on object or instance IDs, names, or string patterns, facilitating the creation of automatic variation in large scenes, specially when coupled with other variation nodes such as asSwitchTexture, asVaryColor or asIdManifold.
Parameters¶
Color Parameters¶
- Input Color 0
- The first material in the list of materials evaluate.
(…)
Note
The subsequent inputs follow exactly the same structure and parameterization.
- Input Color 7
- The last material in the list of materials to evaluate.
- Cycle Mode
- When cycling through the list of materials, if the index goes outside the list bounds, then one has the choice to cycle back to the beginning of the list, or if to clamp to the list size.
- Connected Slots Only
- When enabled (the default behaviour), it will look up and cycle through t he inputs which are connected to upstream material nodes. When disabled it will cycle through all available inputs, even those that aren’t connected to anything at all.
Manifold Parameters¶
- Manifold Type
The type of manifold to use in order to determine which lookup to do in the list of materials. It can be one of the following
- Object Name
- Object Instance Name
- Assembly Name
- Assembly Instance Name
- Face ID
- String Prefix
- String Suffix
- Find String
Outputs¶
- Output Color
- The resulting material color.
Footnotes
| [1] | Regular expressions, or regex. If you’re unfamiliar with it, it allows the creation of complex patterns for string and substring matching. You can validate your expressions here at regex101. |
| [2] | A number used to initialize a pseudo random number generator, to allow some degree of determinism in a system. See random seed for more information. |
asToon¶
A Non-Photo-Realistic/NPR [Gooch:1998:NLM:280814.280950] toon shader.
Parameters¶
Incandescence Parameters¶
- Incandescence Weight
- The amount of incandescence, not restricted to an upper bound of 1.0.
- Incandescence Attenuation
- The amount of attenuation for the incandescence, based on the facing ratio towards the viewer. A high value will darken the values towards the edges.
Toon Control¶
- Incandescence Tint
- The incandescence color.
- Blending Mode
The blending mode for the Incandescence Tint parameter. It can be one of the following modes:
- Darken
- Multiply
- Color Burn
- Linear Burn
- Lighten
- Screen
- Color Dodge
- Linear Dodge
- Overlay
- Soft Light
- Hard Light
- Vivid Light
- Linear Light
- Pin Light
- Difference
- Exclusion
- Subtract
- Divide
- Hue
- Saturation
- Color
- Luminosity
See also
The node asBlendColor for more details.
- EDF Dark Color
- The color to use in the darkest areas of this term [1].
- EDF Dark Level
- The threshold at which to transition from darkest tones to mid-tones.
- EDF Midtone Color
- The color to use for the mid-tones.
- EDF Midtone Level
- The threshold at which to transition from mid-tones to bright areas.
- EDF Bright Color
- The brightest color.
- EDF Softness
- The transition softness between the tonal areas.
Advanced¶
- Normalize by Area
- When unchecked, the incandescence term is constant. When checked, it’s scaled by the surface area of the object. With deforming or scaling objects, the incandescence might therefore change in order to keep the same energy level being emitted per surface area.
Diffuse Parameters¶
- Diffuse Weight
- The contribution of the diffuse term to the toon shading, between 0 and 1.
Toon Control¶
- Diffuse Tint
- The color for the diffuse term.
- Blending Mode
The blending mode for the Diffuse Tint parameter. It can be one of the following modes:
- Darken
- Multiply
- Color Burn
- Linear Burn
- Lighten
- Screen
- Color Dodge
- Linear Dodge
- Overlay
- Soft Light
- Hard Light
- Vivid Light
- Linear Light
- Pin Light
- Difference
- Exclusion
- Subtract
- Divide
- Hue
- Saturation
- Color
- Luminosity
See also
The node asBlendColor for more details.
- Shadow Color
- The color to use in the shadow areas, or umbra.
- Shadow Level
- The threshold at which to transition from shadow to mid-tones.
- Midtone Color
- The color to use for the mid-tones, or penumbra.
- Midtone Level
- The threshold at which to transition from mid-tones to bright areas.
- Highlight Color
- The bright areas color.
- Diffuse Softness
- The transition softness between the tonal areas.
Specular Parameters¶
- Specular Weight
- The amount of specular highlights to add to the shading, between 0 and 1.
- Specular Roughness
- The apparent surface roughness of the specular highlights. This works in conjunction with the Specular Softness parameter to determine the softness of transition from highlights to non lit area. If you want soft highlights, increase roughness and Specular Softness. If you want bigger yet sharper highlights, increase roughness and keep the Specular Softness low.
- Index of Refraction
- The index of refraction for the specular term, with high values increasing the reflectivity, and low values decreasing it. This also works in conjunction with the Specular Softness control.
Anisotropy¶
- Anisotropy Amount
- Overall intensity of the anisotropy, with a value of 0.0 representing a isotropic specular highlight, and 1.0 fully anisotropic along the main anisotropy direction.
- Anisotropy Angle
- Rotation angle for the anisotropic highlight in [0,1], mapping a rotation from 0 to 360 degrees.
- Anisotropy Mode
Toggles between accepting a direct texture map in the form of an anisotropy vector map, or between an explicit vector (or a connection to a node that generates such a vector [2] ). It can take the values
- Anisotropy Map
- Explicit Vector
- Anisotropy Map
- Also known as tangent field, encodes the anisotropy directions along X and Y in the Red and Green or Red and Blue channels of the image. Appleseed expects values encoded in the Red and Green channels. Valid when the Anisotropy Mode is set to Anisotropy Map only.
- Anisotropy Direction
- The explicit vector passed as the anisotropy direction. Valid when the Anisotropy Mode is set to Explicit Vector only.
Toon Controls¶
- Specular Tint
- The color for the specular term.
- Blending Mode
The blending mode for the Specular Tint parameter. It can be one of the following modes:
- Darken
- Multiply
- Color Burn
- Linear Burn
- Lighten
- Screen
- Color Dodge
- Linear Dodge
- Overlay
- Soft Light
- Hard Light
- Vivid Light
- Linear Light
- Pin Light
- Difference
- Exclusion
- Subtract
- Divide
- Hue
- Saturation
- Color
- Luminosity
See also
The node asBlendColor for more details.
- Glossy Color
- The color to use for the specular highlights.
- Glossy Level
- The threshold at which to transition from specular highlights to areas without specular highlights.
- Glossy Softness
- The transition softness between the highlights and areas without highlights. This works in conjunction with Specular Roughness, since a very rough specular highlight will still look sharp if the threshold between the lit areas have a harsh transition. On the other side this gives the user the ability to increase the size of the specular highlights, or decrease them, and vary their apparent softness independently.
- Facing Attenuation
- A viewer Fresnel based attenuation factor. Higher values decrease the intensity of the specular reflection towards the viewer.
Rim Lighting Parameters¶
- Rim Weight
- Amount of contribution of the rim lighting effect.
- Rim Tint
- The color for the rim lighting contribution blend.
- Blending Mode
The blending mode for the Rim Tint parameter. It can be one of the following modes:
- Darken
- Multiply
- Color Burn
- Linear Burn
- Lighten
- Screen
- Color Dodge
- Linear Dodge
- Overlay
- Soft Light
- Hard Light
- Vivid Light
- Linear Light
- Pin Light
- Difference
- Exclusion
- Subtract
- Divide
- Hue
- Saturation
- Color
- Luminosity
See also
The node asBlendColor for more details.
- Rim Softness
- The softness of the rim lighting effect.
Bump Parameters¶
- Bump Normal
- The unit length world space normal of the bumped surface.
- Specular Normal
- When using separate bump controls for the diffuse and specular terms, this is the unit length world space normal for the specular term.
- Bump Control
This allows the user to choose a single bump effect for both the diffuse and specular terms, or a separate bump effect for these terms. When using both, the Bump Normal parameter affects both terms. It can take the following values accordingly:
- Diffuse Affects Both
- Split Bump
Transparency Parameters¶
- Transparency
- The transparency color, affecting shadow tinting as well.
Contour Parameters¶
- Contour Color
- The overall color of the outlines.
- Contour Opacity
- The overall opacity of the outlines.
- Contour Width
- The width of the outlines on the object.
- Contour Object
- Generate the contours based on the object ID.
- Contour Material
- Generate contours based on the material ID. Objects with the same material ID will share contours.
- Contour Occlusion
- Generate contours based on depth differences between nearby points.
- Contour Creases
- Generate contours based on the creases of the object [3], outlining sudden changes of the surface.
- Occlusion Threshold
- The threshold value for the depth difference comparison between nearby points
- Crease Threshold
- The threshold value for the creases based outlining, where low values result in outlines for smaller changes in the surface of the object.
Matte Opacity Parameters¶
- Enable Matte Opacity
- Parameter that toggles matte holdouts.
- Matte Opacity
- Matte opacity scaling factor.
- Matte Opacity Color
- Holdout color.
Outputs¶
- Output Color
- The toon BRDF output color.
- Output Transparency
- The resulting transparency color.
- Output Matte Opacity
- The matte holdout.
Screenshots¶
Footnotes
| [1] | Emittance Distribution Function. |
| [2] | Such as the anisotropy vector field node. |
| [3] | Based on the partial derivatives of the surface normal N along the U and V directions. |
References
| [GGSC98] | Amy Gooch, Bruce Gooch, Peter Shirley, and Elaine Cohen. A non-photorealistic lighting model for automatic technical illustration. In Proceedings of the 25th Annual Conference on Computer Graphics and Interactive Techniques, SIGGRAPH ‘98, 447–452. New York, NY, USA, 1998. ACM. URL: http://doi.acm.org/10.1145/280814.280950, doi:10.1145/280814.280950. |
asNoise2D¶
A fractal noise node, with recursion, and an ample choice of noise primitives.
Parameters¶
Color Parameters¶
- Color 1
- Primary color.
- Color 2
- Secondary color.
- Contrast
- Contrast between primary and secondary colors.
Noise Parameters¶
- Type
The noise primitive used. It can take the following values
- Perlin [Perlin:1985:IS:325165.325247]
- Simplex [Perlin:2002:IN:566654.566636]
- Value
- Voronoise [1] [Worley:1996:CTB:237170.237267]
- Gabor [Galerne:2012:GNE:2185520.2185569], [Lagae:2009:PNU:1531326.1531360]
- Intensity
- The global noise intensity.
- X Frequency
- The noise frequency along the x direction.
- Y Frequency
- The noise frequency along the y direction.
- Ridges
- Toggling this checkbox will enable the Ridged Noise mode. A noise mode more suited to modelling the appearance of crests, mountains, when used to drive a displacement or bump map.
- Inflection
- Enabling this checkbox will force the noise function to return a absolute value (if the noise was in [-1,1] range to begin with, otherwise it won’t have any effect).
- Signed Noise
- Enabling this checkbox makes the noise function return values in the [-1,1] range, and disabling it will return values in [0,1] range.
Motion Parameters¶
- Animated Noise
- Enabling this checkbox will animate the noise along time.
- Frame Time
- Frame time, typically the frame number.
- Time Scale
- Global time scale, affects the frame time.
Periodic Parameters¶
- Periodic
- Enabling this checkbox will enable periodic noise, with a user-set x and y period.
- X Period
- The x period when using periodic noise.
- Y Period
- The y period when using periodic noise.
Voronoise Parameters¶
- Smoothness
- Controls the smoothness of the generalized Voronoi noise, with low values having a sharp cell boundary, and high values having a smooth Perlin noise like appearance.
- Jittering
- Controls the jittering of the Voronoi cells, with low values producing a regular cell grid, and high values producing a randomized cell grid.
Gabor Parameters¶
- Anisotropy
This parameter controls the type of Gabor noise used. It can take the values
- Isotropic
- Anisotropic
- Hybrid
- Direction
- Anisotropy vector to use when the Gabor noise Anisotropy mode is set to Anisotropic.
- Bandwidth
- The bandwidth for the Gabor noise.
- Impulses
- The number of impulses for the Gabor noise.
- Filter Noise
- Enabling this checkbox will produce antialiased noise.
Recursion Parameters¶
- Amplitude
- Initial noise amplitude before recursion.
- Octaves
- The number of interations to perform.
- Cascade
The type of iteration to perform. It can be
- Additive
- Multiplicative
In the first case, the results of each iteration are accumulated, and in the second case, they are multiplied with the previous product.
- Lacunarity
- Control for the gap between successive noise frequencies (sucessive octaves).
- Offset
- Controls the multifractality.
- Gain
- Controls the contrast of the fractal.
- Distortion
- This parameter distorts the domain of the coordinates for each frequency.
Outputs¶
- Output Color
- The color resulting from ghe Features Mode choice.
- Output Alpha
- The alpha resulting from the Features Mode choice, usually luminance of the color only.
Screenshots¶
Some examples of what can be achieved, and is provided as presets.
Footnotes
| [1] | Also known as generalized Voronoi. See Inigo Quilez article on voronoise. |
References
| [GLLD12] | Bruno Galerne, Ares Lagae, Sylvain Lefebvre, and George Drettakis. Gabor noise by example. ACM Trans. Graph., 31(4):73:1–73:9, July 2012. URL: http://doi.acm.org/10.1145/2185520.2185569, doi:10.1145/2185520.2185569. |
| [LLDDutre09] | Ares Lagae, Sylvain Lefebvre, George Drettakis, and Philip Dutré. Procedural noise using sparse gabor convolution. ACM Trans. Graph., 28(3):54:1–54:10, jul 2009. URL: http://doi.acm.org/10.1145/1531326.1531360, doi:10.1145/1531326.1531360. |
| [Per85] | Ken Perlin. An image synthesizer. SIGGRAPH Comput. Graph., 19(3):287–296, jul 1985. URL: http://doi.acm.org/10.1145/325165.325247, doi:10.1145/325165.325247. |
| [Per02] | Ken Perlin. Improving noise. ACM Trans. Graph., 21(3):681–682, jul 2002. URL: http://doi.acm.org/10.1145/566654.566636, doi:10.1145/566654.566636. |
| [Wor96] | Steven Worley. A cellular texture basis function. In Proceedings of the 23rd Annual Conference on Computer Graphics and Interactive Techniques, SIGGRAPH ‘96, 291–294. New York, NY, USA, 1996. ACM. URL: http://doi.acm.org/10.1145/237170.237267, doi:10.1145/237170.237267. |
asNoise3D¶
A fractal solid noise node, with recursion, and an ample choice of noise primitives. The 3D counterpart of asNoise2D using the surface point P and a placement matrix, instead of UV coordinates.
Parameters¶
Color Parameters¶
- Color 1
- Primary color.
- Color 2
- Secondary color.
- Contrast
- Contrast between primary and secondary colors.
Noise Parameters¶
- Type
The noise primitive used. It can take the following values
- Perlin [Perlin:1985:IS:325165.325247]
- Simplex [Perlin:2002:IN:566654.566636]
- Value
- Voronoise [1] [Worley:1996:CTB:237170.237267]
- Gabor [Galerne:2012:GNE:2185520.2185569], [Lagae:2009:PNU:1531326.1531360]
- Intensity
- The global noise intensity.
- Frequency
- The noise frequency along the x, y and z directions, contained in a vector.
- Ridges
- Toggling this checkbox will enable the Ridged Noise mode. A noise mode more suited to modelling the appearance of crests, mountains, when used to drive a displacement or bump map.
- Inflection
- Enabling this checkbox will force the noise function to return a absolute value (if the noise was in [-1,1] range to begin with, otherwise it won’t have any effect).
- Signed Noise
- Enabling this checkbox makes the noise function return values in the [-1,1] range, and disabling it will return values in [0,1] range.
Motion Parameters¶
- Animated Noise
- Enabling this checkbox will animate the noise along time.
- Frame Time
- Frame time, typically the frame number.
- Time Scale
- Global time scale, affects the frame time.
Periodic Parameters¶
- Periodic
- Enabling this checkbox will enable periodic noise, with a user-set x, y and z period.
- Period
- The periodic noise x, y and z frequency, encoded in a vector.
Voronoise Parameters¶
- Smoothness
- Controls the smoothness of the generalized Voronoi noise, with low values having a sharp cell boundary, and high values having a smooth Perlin noise like appearance.
- Jittering
- Controls the jittering of the Voronoi cells, with low values producing a regular cell grid, and high values producing a randomized cell grid.
Gabor Parameters¶
- Anisotropy
This parameter controls the type of Gabor noise used. It can take the values
- Isotropic
- Anisotropic
- Hybrid
- Direction
- Anisotropy vector to use when the Gabor noise Anisotropy mode is set to Anisotropic.
- Bandwidth
- The bandwidth for the Gabor noise.
- Impulses
- The number of impulses for the Gabor noise.
- Filter Noise
- Enabling this checkbox will produce antialiased noise.
Recursion Parameters¶
- Amplitude
- Initial noise amplitude before recursion.
- Octaves
- The number of interations to perform.
- Cascade
The type of iteration to perform. It can be
- Additive
- Multiplicative
In the first case, the results of each iteration are accumulated, and in the second case, they are multiplied with the previous product.
- Lacunarity
- Control for the gap between successive noise frequencies (sucessive octaves).
- Offset
- Controls the multifractality.
- Gain
- Controls the contrast of the fractal.
- Distortion
- This parameter distorts the domain of the coordinates for each frequency.
Outputs¶
- Output Color
- The color resulting from ghe Features Mode choice.
- Output Alpha
- The alpha resulting from the Features Mode choice, usually luminance of the color only.
Screenshots¶
Some examples of what can be achieved with this node, besides what was illustrated by the asNoise2D gallery.
Footnotes
| [1] | Also known as generalized Voronoi. See Inigo Quilez article on voronoise. |
References
| [GLLD12] | Bruno Galerne, Ares Lagae, Sylvain Lefebvre, and George Drettakis. Gabor noise by example. ACM Trans. Graph., 31(4):73:1–73:9, July 2012. URL: http://doi.acm.org/10.1145/2185520.2185569, doi:10.1145/2185520.2185569. |
| [LLDDutre09] | Ares Lagae, Sylvain Lefebvre, George Drettakis, and Philip Dutré. Procedural noise using sparse gabor convolution. ACM Trans. Graph., 28(3):54:1–54:10, jul 2009. URL: http://doi.acm.org/10.1145/1531326.1531360, doi:10.1145/1531326.1531360. |
| [Per85] | Ken Perlin. An image synthesizer. SIGGRAPH Comput. Graph., 19(3):287–296, jul 1985. URL: http://doi.acm.org/10.1145/325165.325247, doi:10.1145/325165.325247. |
| [Per02] | Ken Perlin. Improving noise. ACM Trans. Graph., 21(3):681–682, jul 2002. URL: http://doi.acm.org/10.1145/566654.566636, doi:10.1145/566654.566636. |
| [Wor96] | Steven Worley. A cellular texture basis function. In Proceedings of the 23rd Annual Conference on Computer Graphics and Interactive Techniques, SIGGRAPH ‘96, 291–294. New York, NY, USA, 1996. ACM. URL: http://doi.acm.org/10.1145/237170.237267, doi:10.1145/237170.237267. |
asTexture¶
A texture lookup node with full control over OSL’s texture() call.
Parameters¶
Texture
- Filename
- The texture filename
- Atlas Type
The texture atlas type, it can be one of
Note
Though a full reference of UV tiles is outside the scope of this document, it suffices to say here that the ZBrush UV tiles pattern is in the form u<N>_v<N> with the tiles starting at 0, whilst Mudbox shares the same pattern but starts at 1. Mari uses the form <UDIM>. All a user needs to do is to point at the filename and choose the respective texture atlas type, and this node should take care of doing the appropriate string substitutions. See also the Maya documentation on UV tiles.
- Color
- The default color to use if the texture lookup fails for any reason.
- Alpha
- The default alpha value if there is none in the texture file, or if the lookup of the alpha channel fails for any reason.
- Starting Channel
- The starting channel for the texture lookup. For an RGBA texture, the starting channel is 0, which is also the default.
- S Blur Amount
- The amount of blur along the s texture coordinate, defaulting to 0.
- T Blur Amount
- The amount of blur along the t texture coordinate, defauling to 0.
- S Filter Width
- A scaling factor for the size of the texture filter as defined by the differentials or implicitly by the differentials of the s texture coordinates, with a default value of 1.0. A value of 0.0 turns off texture filtering.
- T Filter Width
- A scaling factor for the size of the texture filter as defined by the differentials or implicitly by the differentials of the t texture coordinates, with a default value of 1.0. A value of 0.0 turns off texture filtering.
- S Wrap
The texture wrapping mode along the s direction, which can be one of
- Default (the texture system default)
- Black
- Periodic
- Clamp
- Mirror
- T Wrap
The texture warpping mode along the t direction, which can be one of
- Default (the texture system default)
- Black
- Periodic
- Clamp
- Mirror
- Interpolation Method
The texture interpolation method, which can take the following values
- Smart Cubic (default)
- Cubic
- Linear
- Closest
See also
This link on texture filtering for more details.
Color Management¶
- Enable CMS
- Toggles the color management options on or off.
- Input Transfer Function
Applies an Electro-Optical Transfer Function, or EOTF, to the input texture, linearizing it. It can take the following values
- None/Raw
- sRGB
- Rec.709
- Gamma 2.2
- Gamma 2.4
- Gamma 2.6 (DCI)
- Rec.1886 [3]
- Rec.2020
- RGB Primaries
It allows the user to set the RGB primaries that define the color space of the input texture, and can take the following values
- Rendering RGB Primaries
It allows the user to set the RGB primaries of the rendering or working space, and it should match the choice of rendering/working space of the renderer. It can take the following values
- sRGB/Rec.709
- Rec.2020
- DCI-P3
- ACES
- ACEScg
Texture Coordinates¶
- UV Coords
- The uv texture coordinates.
- UV Filter Size
- The computed filter size for the uv texture coordinates.
Outputs¶
- Output Color
- The color resulting from the Features Mode choice.
- Output Alpha
- The alpha resulting from the Features Mode choice, usually luminance of the color only.
- Output Single Channel
- The output when the texture lookup is made on a greyscale image.
Footnotes
| [1] | For the ZBrush and Mudbox case, the UV tiles are assumed to be separated by underscores. |
| [2] | This note assumes however, that the UDIM pattern will always come last before the filename extension. That is, if you are using an animated sequence or frames of an animated sequence, then the padded frame numbers must come before the UDIM pattern. I.e, <filename>.<padded frame numbers>.<UDIM>.<extension>. |
| [3] | See ITU-R BT.1886 recommendation for details on the electro-optical transfer function. |
| [4] | Because it makes no sense whatsoever to use colorimetry on non-color information or data, such as normal maps, or Z depth, motion vectors, and so on. |
| [5] | sRGB shares the same CIE xy chromaticity coordinates with ITU-R BT.709/Rec.709 , hence this node refers to the RGB primaries shared by these two color spaces as sRGB/Rec.709. |
| [6] | See encoding characteristics of AdobeRGB specification. |
References
| [DFD+15] | Haarm-Pieter Duiker, Alexander Forsythe, Scott Dyer, Ray Feeney, Will McCown, Jim Houston, Andy Maltz, and Doug Walker. Acescg: a common color encoding for visual effects applications. In Proceedings of the 2015 Symposium on Digital Production, DigiPro ‘15, 53–53. New York, NY, USA, 2015. ACM. URL: http://doi.acm.org/10.1145/2791261.2791273, doi:10.1145/2791261.2791273. |
| [Ini11] | Digital Cinema Initiatives. Rp 431-2:2011 - smpte recommended practice - d-cinema quality #x2014; reference projector and environment. SMPTE RP 431-2:2011, pages 1–14, April 2011. doi:10.5594/SMPTE.RP431-2.2011. |
| [oMPAS12] | The Academy of Motion Picture Arts and Sciences. St 2065-1:2012 - smpte standard - academy color encoding specification (aces). ST 2065-1:2012, pages 1–23, April 2012. doi:10.5594/SMPTE.ST2065-1.2012. |
| [SCW14] | M. Sugawara, S. Y. Choi, and D. Wood. Ultra-high-definition television (rec. itu-r bt.2020): a generational leap in the evolution of television [standards in a nutshell]. IEEE Signal Processing Magazine, 31(3):170–174, May 2014. doi:10.1109/MSP.2014.2302331. |
asTexture3D¶
A node that performs 3D lookup of a volume texture, typically a Field3D file.
Parameters¶
3D Texture¶
- Filename
- The volume texture, typically a *.f3d [1] file.
- Starting Channel
- The starting channel for the volume texture lookup.
- Color
- The default color to use if the texture lookup fails.
- Channel Fill
- The default scalar value to use for any channels requested but not present in the volume texture.
- Time
- The time value to use if the texture specifies a time varying local transformation.
Wrapping¶
- S Wrap
The wrapping mode along the s coordinate, it can be one of
- Default
- Black
- Periodic
- Clamp
- Mirror
- T Wrap
The wrapping mode along the t coordinate, it can be one of
- Default
- Black
- Periodic
- Clamp
- Mirror
- R Wrap
The wrapping mode along the r coordinate, it can be one of
- Default
- Black
- Periodic
- Clamp
- Mirror
Blur¶
- Blur Width
- The amount of blur along the width of the volume, or the s direction.
- Blur Height
- The amount of blur along the height of the volume, or t direction.
- Blur Depth
- The amount of blur along the depth of the volume, or r direction.
Filter¶
- Width Filter
- Scale for the size of the filter defined by the partial derivatives along the s direction or implicitly from P, with a value of 0 disabling filtering altogether.
- Height Filter
- Scale for the size of the filter defined by the partial derivatives along the t direction or implicitly from P, with a value of 0 disabling filtering altogether.
- Depth Filter
- Scale for the size of the filter defined by the partial derivatives along the r direction or implicitly from P, with a value of 0 disabling filtering altogether.
Coordinates¶
- Surface Point
- The surface point being shaded.
- Coordinate System
The coordinate system to use for the volume, it can be
- Object Space
- World Space
- Camera Space
Outputs¶
- Output Color
- The color resulting from the Features Mode choice.
Footnotes
| [1] | These files are exported as a result of simulations done in other applications. In the case of Maya, one could for instance convert Maya’s fluids to a Field3d file via the Field3D Maya Plugin. Other simulation applications also allow exporter volume data as *.f3d. |
asVoronoi2D¶
A procedural 2D Worley [Worley:1996:CTB:237170.237267] like noise shader, that outputs not only the resulting color, but the four nearest features to the evaluated point, their respective positions, and their cell color IDs. See also [Ebert:2002:TMP:572337].
Parameters¶
Color Parameters¶
- Color 1
- Primary cell color.
- Color 2
- Secondary cell color.
- Contrast
- Contrast between primary and secondary cell color.
Recursion Parameters¶
- Amplitude
- Controls the amplitute at each octave, including the starting iteration.
- Octaves
- Number of iterations to perform, higher values lead to increasing detail, but increased computational cost as well.
- Lacunarity
- Defines how large the gaps are in the cell noise with increasing octaves, higher values lead to higher gaps, lower values to small gaps.
- Persistence
- The persistence of the fractal is a gain factor to apply to the amplitude at each iteration, but it only has an effect when the shader is set to the mode pebbles.
Cell Parameters¶
- Density
- The density of the cells, with higher values resulting in a higher number of cells in the same area.
- Jittering
- How random the placement of the cells is, with low values resulting in a ordered grid of cells, and higher values resulting in aleatory placement of cells.
- Metric
- Which metric to choose to calculate the distance from cell to feature points. There are several to choose from, resulting in different types of patterns.
- Euclidian distance [1]
- Sum of square difference
- Tchebychev distance [2]
- Sum of absolute difference
- Akritean distance
- Minkowski metric [3]
- Karlsruhe metric [4]
The sum of the square difference is also known as the Manhattan metric [5].
The Minkowski metric is a generalized metric whose P parameter allows you to go from the Euclidian distance when P has a value of 2, to the Manhattan distance when P has a value of 1, and as P reaches infinity, it represents the Tchebychev metric.
The Akritean distance if a weighted mix of the Euclidian distance, and the Tchebychev distance.
The Karlsruhe metric, also known as Moscow metric, is a radial metric, returns radial sections from a cell at the center.
- Minkowski Parameter
- Controls the metric, with a value of 1 being the Manhattan distance, 2 being the Euclidian distance, and higher values tending to the Tchebychev metric as the parameter approaches infinity.
- Coverage
- The Akritean distance coverage, or the weighting mix between the Euclidian distance and the Tchebychev distance.
- Features Mode
- The features mode to use when computing the output color.
- Feature 1, or nearest feature from the cell
- Feature 2, or second nearest feature from the cell
- Feature 3, or third nearest feature from the cell
- Feature 4, or fourth nearest feature from the cell
- F1 + F2, or sum of first and second nearest features
- F2 - F1, or difference between second and first nearest features
- F1 * F2, or product of first and second nearest features
- F1 / F2, or division of first nearest feature by second nearest feature
- F1 ^ F2, nearest feature raised to the second nearest feature
- Pebbles, a mode that resembles pebbles
- Cell ID 1, the ID of the nearest feature to the cell
- Cell ID 2, the ID of the second nearest feature to the cell
- Cell ID 3, the ID of the third nearest feature to the cell
- Cell ID 4, the ID of the fourth nearest feature to the cell
Note
The unmodified features, points and their color IDs are also output from the shader, giving the user greater creative potential. The feature modes above are but a starting point.
Color Balance¶
The standard Maya color balance, gain, offset parameters. Please consult Maya’s documentation for more information on these controls.
Effects¶
The standard Maya effects parameters. Please consult Maya’s documentation for more information on these controls.
Coordinates¶
The input UV coordinates, typically from an upstream placement2d node.
Outputs¶
- Output Color
- The color resulting from ghe Features Mode choice.
- Output Alpha
- The alpha resulting from the Features Mode choice, usually luminance of the color only.
- Output Features
- An array of 4 floats, containing the four nearest features to the cell.
- Output Positions
- An array of 4 points, containing the center of the four nearest features to the cell.
- Output IDs
- An array of 4 colors, containing the color IDs of the four nearest features to the cell.
Warning
presently OSL does not allow connections from/to array elements, and appleseed-maya is not enabling the array outputs for now. This will be addressed in a future release.
Screenshots¶
Some examples of feature output modes and metrics.
Footnotes
| [1] | The Euclidian distance or Euclidian metric, also known as  norm, is the straight line distance between two points in Euclidian space. |
| [2] | The Chebyshev (or Tchebychev) distance, also known as Chessboard distance or  norm, is a metric on a vector space where the distance between two vectors is the greatest of their differences along any coordinate dimension. |
| [3] | The Minkowski distance, also known as  norm, is a metric which is a generalization of both the Euclidian distance and the Manhattan distance, being equal to the Manhattan distance when its p parameter is equal to 1, or equal to the Euclidian distance when its p parameter is equal to 2. On the limit as p approaches infinity, it is equal to the Chebyshev distance. |
| [4] | In metric geometry, the Karlsruhe metric is a measure of distance that assumes travel is only possible along rays through the origin and circular arcs centered at the origin. |
| [5] | The Manhattan distance, also known as taxicab metric or  norm, is a metric in which the distance between two points is the sum of the absolute differences of their Cartesian coordinates. |
References
| [EMP+02] | David S. Ebert, F. Kenton Musgrave, Darwyn Peachey, Ken Perlin, and Steven Worley. Texturing and Modeling: A Procedural Approach. Morgan Kaufmann Publishers Inc., San Francisco, CA, USA, 3rd edition, 2002. ISBN 1558608486. |
| [Wor96] | Steven Worley. A cellular texture basis function. In Proceedings of the 23rd Annual Conference on Computer Graphics and Interactive Techniques, SIGGRAPH ‘96, 291–294. New York, NY, USA, 1996. ACM. URL: http://doi.acm.org/10.1145/237170.237267, doi:10.1145/237170.237267. |
asVoronoi3D¶
A procedural 3D Worley [Worley:1996:CTB:237170.237267] like noise shader, that outputs not only the resulting color, but the four nearest features to the evaluated point, their respective positions, and their cell color IDs. See also [Ebert:2002:TMP:572337].
Parameters¶
Color Parameters¶
- Color 1
- Primary cell color.
- Color 2
- Secondary cell color.
- Contrast
- Contrast between primary and secondary cell color.
Recursion Parameters¶
- Amplitude
- Controls the amplitute at each octave, including the starting iteration.
- Octaves
- Number of iterations to perform, higher values lead to increasing detail, but increased computational cost as well.
- Lacunarity
- Defines how large the gaps are in the cell noise with increasing octaves, higher values lead to higher gaps, lower values to small gaps.
- Persistence
- The persistence of the fractal is a gain factor to apply to the amplitude at each iteration, but it only has an effect when the shader is set to the mode pebbles.
Cell Parameters¶
- Density
- The density of the cells, with higher values resulting in a higher number of cells in the same area.
- Jittering
- How random the placement of the cells is, with low values resulting in a ordered grid of cells, and higher values resulting in aleatory placement of cells.
- Metric
- Which metric to choose to calculate the distance from cell to feature points. There are several to choose from, resulting in different types of patterns.
- Euclidian distance [1]
- Sum of square difference
- Tchebychev distance [2]
- Sum of absolute difference
- Akritean distance
- Minkowski metric [3]
- Karlsruhe metric [4]
The sum of the square difference is also known as the Manhattan metric [5].
The Minkowski metric is a generalized metric whose P parameter allows you to go from the Euclidian distance when P has a value of 2, to the Manhattan distance when P has a value of 1, and as P reaches infinity, it represents the Tchebychev metric.
The Akritean distance if a weighted mix of the Euclidian distance, and the Tchebychev distance.
The Karlsruhe metric, also known as Moscow metric, is a radial metric, returns radial sections from a cell at the center.
- Minkowski Parameter
- Controls the metric, with a value of 1 being the Manhattan distance, 2 being the Euclidian distance, and higher values tending to the Tchebychev metric as the parameter approaches infinity.
- Coverage
- The Akritean distance coverage, or the weighting mix between the Euclidian distance and the Tchebychev distance.
- Features Mode
- The features mode to use when computing the output color.
- Feature 1, or nearest feature from the cell
- Feature 2, or second nearest feature from the cell
- Feature 3, or third nearest feature from the cell
- Feature 4, or fourth nearest feature from the cell
- F1 + F2, or sum of first and second nearest features
- F2 - F1, or difference between second and first nearest features
- F1 * F2, or product of first and second nearest features
- F1 / F2, or division of first nearest feature by second nearest feature
- F1 ^ F2, nearest feature raised to the second nearest feature
- Pebbles, a mode that resembles pebbles
- Cell ID 1, the ID of the nearest feature to the cell
- Cell ID 2, the ID of the second nearest feature to the cell
- Cell ID 3, the ID of the third nearest feature to the cell
- Cell ID 4, the ID of the fourth nearest feature to the cell
Note
The unmodified features, points and their color IDs are also output from the shader, giving the user greater creative potential. The feature modes above are but a starting point.
Color Balance¶
The standard Maya color balance, gain, offset parameters. Please consult Maya’s documentation for more information on these controls.
Effects¶
The standard Maya effects parameters. Please consult Maya’s documentation for more information on these controls.
Coordinates¶
Typically, the placement 3d node’s placement matrix, which provides a placement matrix to transform the surface point providing the x,y,z coordinates. By default this point is the global primitive variable P, but the user can override this if needed.
Outputs¶
- Output Color
- The color resulting from ghe Features Mode choice.
- Output Alpha
- The alpha resulting from the Features Mode choice, usually luminance of the color only.
- Output Features
- An array of 4 floats, containing the four nearest features to the cell.
- Output Positions
- An array of 4 points, containing the center of the four nearest features to the cell.
- Output IDs
- An array of 4 colors, containing the color IDs of the four nearest features to the cell.
Warning
presently OSL does not allow connections from/to array elements, and appleseed-maya is not enabling the array outputs for now. This will be addressed in a future release.
Screenshots¶
Some examples of different metrics and feature output combinations used.
Footnotes
| [1] | The Euclidian distance or Euclidian metric, also known as norm, is the straight line distance between two points in Euclidian space. |
| [2] | The Chebyshev (or Tchebychev) distance, also known as Chessboard distance or norm, is a metric on a vector space where the distance between two vectors is the greatest of their differences along any coordinate dimension. |
| [3] | The Minkowski distance, also known as norm, is a metric which is a generalization of both the Euclidian distance and the Manhattan distance, being equal to the Manhattan distance when its p parameter is equal to 1, or equal to the Euclidian distance when its p parameter is equal to 2. On the limit as p approaches infinity, it is equal to the Chebyshev distance. |
| [4] | In metric geometry, the Karlsruhe metric is a measure of distance that assumes travel is only possible along rays through the origin and circular arcs centered at the origin. |
| [5] | The Manhattan distance, also known as taxicab metric or norm, is a metric in which the distance between two points is the sum of the absolute differences of their Cartesian coordinates. |
References
| [EMP+02] | David S. Ebert, F. Kenton Musgrave, Darwyn Peachey, Ken Perlin, and Steven Worley. Texturing and Modeling: A Procedural Approach. Morgan Kaufmann Publishers Inc., San Francisco, CA, USA, 3rd edition, 2002. ISBN 1558608486. |
| [Wor96] | Steven Worley. A cellular texture basis function. In Proceedings of the 23rd Annual Conference on Computer Graphics and Interactive Techniques, SIGGRAPH ‘96, 291–294. New York, NY, USA, 1996. ACM. URL: http://doi.acm.org/10.1145/237170.237267, doi:10.1145/237170.237267. |
asAnisotropyVectorField¶
A node that manipulates anisotropy vector maps and outputs a anisotropy vector for use in BxDFs that support anisotropy.
Parameters¶
Field Parameters¶
- Field Color
- The anisotropy vector map color.
- Rotation Angle
- A rotation angle, in degrees, from -360 to 360 degrees, to rotate the input anisotropy vector map. This is an absolute value to re-orient the initial anisotropy vector map, non-texturable.
- Field Mode
The input anisotropy vector map can have the anisotropy directions along X and Y, encoded in the Red and Green channels, or in the Red and Blue channels. Typically, RG encoding is used in applications such as RenderMan [1], while RB encoding is used in applications such as Modo [2] or Softimage [3]. The values allowed are therefore
- Red/Green as XY
- Red/Blue as XY
Rotation Parameters¶
- Rotation Value
- This parameter rotates the RG or RB vector field, and unlike the Rotation Angle parameter, this parameter takes as inputs values between 0.0 and 1.0, and is texturable. Internally this is mapped to [0,360] degrees.
- Rotation Mode
The rotation computed earlier in Rotation Value can be added to the vector field, or the rotation can be applied to both directions along a central axis. That is, the rotation can be mapped from the input [0,1] values to [0,360] degrees (Absolute), or to [-360,360] degrees (Centered) - where a value of 0.5 means no rotation. Values below 0.5 means counter-clockwise rotation, and values above 0.5 imply clockwise rotation. The allowed modes are therefore
- Centered
- Absolute
Output Parameters¶
- Normalize Output
- Parameter that forces a normalization of the final anisotropy vector. The default is to enable it.
Surface Normal¶
- Surface Normal
- The world space, unit length shading normal, bump mapped. Not a tangent space nor a object space normal.
Outputs¶
- Anisotropy Vector
- The final re-oriented, RG or RB encoded anisotropy vector.
Footnotes
| [1] | See RenderMan’s tangent field for details on PRman’s implementation. |
| [2] | See Modo anisotropy help for details on the Modo implementation. Unlike PRman’s, the XY data is encoded in R and B channels, not R and G. |
| [3] | See Softimage anisotropy patterns. Like Modo, the anisotropy data is encoded in the R and B channels. |
asAttributes¶
A node that exposes to the user the general attributes specified in OSL [1] and the appleseed renderer specific attributes.
Parameters¶
This node has no input parameters.
Outputs¶
- Assembly Instance ID
- An integer value containing the ID of an assembly [2] instance.
- Assembly Instance Name
- A string containing the name of the assembly instance.
- Assembly Name
- A string containing the name of the assembly.
- Camera Clip Far
- The farthest camera clipping plane.
- Camera Clip Near
- The nearest camera clipping plane.
- Camera FOV
- The camera Field Of View [3].
- Camera Pixel Aspect
- The camera pixel aspect.
- Camera Projection
- The camera projection.
- Camera Resolution X
- The camera X resolution.
- Camera Resolution Y
- The camera Y resolution.
- Screen Window X Max
- The screen window x maximum value.
- Screen Window X Min
- The screen window x minimum value.
- Screen Window Y Max
- The screen window y maximum value.
- Screen Window Y Min
- The screen window y minimum value.
- Shutter Close Time
- The shutter closing time.
- Shutter Open Time
- The shutter opening time.
- Object Instance ID
- An integer containing an object instance’s ID.
- Object Instance Index
- An integer containing an object instance’s index.
- Object Instance Name
- A string containing the object instance’s name.
- Object Name
- A string containing an object’s name.
- Ray Differentials
- An boolean denoting if the path being traced has ray differentials.
- Ray Depth
- A integer denoting the present ray depth.
- Ray IOR
- The absolute index of refraction of the medium the present ray is travelling in. This is affected by nested dielectrics [ND.2002.10487555].
- Ray Length
- The current path’s length.
Footnotes
| [1] | OSL or Open Shading Language. |
| [2] | See appleseed’s wiki entry for assemblies concepts and procedural assemblies. |
| [3] | See field of view wikipedia page <https://en.wikipedia.org/wiki/Field_of_view> for more details. |
References
| [SB02] | Charles M. Schmidt and Brian Budge. Simple nested dielectrics in ray traced images. Journal of Graphics Tools, 7(2):1–8, 2002. URL: https://doi.org/10.1080/10867651.2002.10487555, arXiv:https://doi.org/10.1080/10867651.2002.10487555, doi:10.1080/10867651.2002.10487555. |
asBlendColor¶
A node that allows the user to blend an input color with a second input color according to preset modes, similar to what is commonly found in image editing applications.
Parameters¶
Color Parameters¶
- Source Color
- The input RGB color.
- Source
- The input color weight.
- Blend Color
- The second input color.
- Blend Weight
- The second input color weight.
- Blend Mode
The blend mode [1] to use for the respective colors. Users of applications such as GIMP or Adobe® Photoshop® should be familiar with these blend operations. They can take the following values
- Darken
- Multiply
- Color Burn
- Linear Burn
- Lighten
- Screen
- Color Dodge
- Linear Dodge
- Overlay
- Soft Light
- Hard Light
- Vivid Light
- Linear Light
- Pin Light
- Difference
- Exclusion
- Subtract
- Divide
- Hue
- Saturation
- Color
- Luminosity
See also
Merging and Transformation of Raster Images for Cartoon Animation [Wallace:1981:MTR:965161.806813].
- Clamp Output
- Checking this checkbox will clamp the output to the [0,1] range.
Outputs¶
- Output Color
- The blended color result.
Footnotes
| [1] | See this page on blend modes for more information. |
References
| [Wal81] | Bruce A. Wallace. Merging and transformation of raster images for cartoon animation. SIGGRAPH Comput. Graph., 15(3):253–262, August 1981. URL: http://doi.acm.org/10.1145/965161.806813, doi:10.1145/965161.806813. |
asBump¶
A node that allows the user to apply scalar bump mapping, or normal mapping.
Parameters¶
Mode Parameters¶
- Mode
The choice of bump mapping algorithm to use. It can be one of:
Bump Parameters¶
- Bump Value
- A scalar value controlling the magnitude of the bump effect.
- Bump Depth
- A scalar value controlling the bump depth of the bump effect. Unlike the bump value which expects a value in [0,1] range, the bump depth can be a positive or negative value, in which case it will apply the bump effect outwards or inwards respectively.
Normal Map¶
- Normal Map Weight
- A scaling factor that defines the contribution weight of the normal map. With a value of 0.0, no contribution takes place and the regular surface normal is used. A value of 1.0 defines full contribution of the normal map input.
- Normal Map
- The input normal map color.
- Map Coordinate System
The coordinate system of the input normal map used [1]. It can be one of:
- Tangent Space
- Object Space
- World Space
Advanced Parameters¶
- Map Signedness
- The signedness of the input normal map. If your map is in [-1,1] range, use Signed. If your map is in [0,1] range, used Unsigned.
- Flip R
- Flip the red channel of the input tangent space normal map.
- Flip G
- Flip the green channel of the input tangent space normal map.
- Swap RG
- Swap the red and green channels of the input tangent space normal map.
Note
The channel flipping and swapping options only have effect on the tangent space normal maps. They are ignored when the Map Coordinate System is Object Space or World Space.
Surface Parameters¶
- Surface Normal
- The base surface normal to use. It can be the result of a previous bump node, or the global variable N from the asAttributes node. If not set, it defaults to the (world space) surface normal N.
Outputs¶
- Result
- The unit length world space bumped normal.
Footnotes
| [1] | Usually one uses tangent space normal maps, but the option is provided here to use object and world space normal maps, which sometimes can be exported from other applications. |
References
| [Bli78] | James F. Blinn. Simulation of wrinkled surfaces. SIGGRAPH Comput. Graph., 12(3):286–292, August 1978. URL: http://doi.acm.org/10.1145/965139.507101, doi:10.1145/965139.507101. |
| [CMSR98] | P. Cignoni, C. Montani, R. Scopigno, and C. Rocchini. A general method for preserving attribute values on simplified meshes. In Proceedings of the Conference on Visualization ‘98, VIS ‘98, 59–66. Los Alamitos, CA, USA, 1998. IEEE Computer Society Press. URL: http://dl.acm.org/citation.cfm?id=288216.288224. |
| [COM98] | Jonathan Cohen, Marc Olano, and Dinesh Manocha. Appearance-preserving simplification. In Proceedings of the 25th Annual Conference on Computer Graphics and Interactive Techniques, SIGGRAPH ‘98, 115–122. New York, NY, USA, 1998. ACM. URL: http://doi.acm.org/10.1145/280814.280832, doi:10.1145/280814.280832. |
asColorTransform¶
A node that transforms a color from any input color model, to any output color model, respecting the color space definitions set in synColor CMS options. An option will be added later to override this, in a way similar to what is presently done in the luminance shader.
Parameters¶
Color Attributes¶
- Input Color
- The color being transformed.
- Input Space
The input color space to transform from. It can be one of
- RGB
- HSV [1]
- HSL [2]
- CIE XYZ [3]
- CIE xyY [4]
- CIE 1976 L*a*b* [COTE:COTE338]
- CIE 1976 L*u*v* [Poynton:2012:DVH:2222488]
- CIE 1976 LCh ab [5]
- CIE 1976 LCh uv [6]
- Output Space
The output color space to transform to. It can be one of
- RGB
- HSV
- HSL
- CIE XYZ
- CIE xyY
- CIE 1976 L*a*b*
- CIE 1976 L*u*v*
- CIE 1976 LCh ab
- CIE 1976 LCh uv
See also
The Colour Python colour science package for extensive information on the topic :cite:` [mansencal_thomas_2018_1175177]
Outputs¶
- Result
- The transformed color. For usability, the range of some spaces are remapped to the [0,1] range. As an example, the hue could be mapped to a greyscale texture, or if the space is set to CIE 1976 L*a*b*, the a variable would control the green/magenta oposition, while the b variable would control the blue/yellow oposition, with respective neutral/grey values at 0.5.
Screenshots¶
Some examples of color transformations.
Footnotes
| [1] | Hue, Saturation, Value color space, https://en.wikipedia.org/wiki/HSL_and_HSV |
| [2] | Hue, Saturation, Lightness color space, https://en.wikipedia.org/wiki/HSL_and_HSV |
| [3] | The CIE XYZ color space, https://en.wikipedia.org/wiki/CIE_1931_color_space |
| [4] | CIE xyY, https://en.wikipedia.org/wiki/CIE_1931_color_space |
| [5] | Cylindrical representation of the CIELAB color space, LCh ab co, https://en.wikipedia.org/wiki/Lab_color_space#Cylindrical_representation:_CIELCh_or_CIEHLC |
| [6] | Cylindrical representation of the CIELUV color space, CIE LCh uv, https://en.wikipedia.org/wiki/Lab_color_space#Cylindrical_representation:_CIELCh_or_CIEHLC |
References
| [MMP+18] | Thomas Mansencal, Michael Mauderer, Michael Parsons, Luke Canavan, Sean Cooper, Nick Shaw, Kevin Wheatley, Katherine Crowson, and Ofek Lev. Colour 0.3.11. February 2018. URL: https://doi.org/10.5281/zenodo.1175177, doi:10.5281/zenodo.1175177. |
| [McL76] | K. McLAREN. Xiii—the development of the cie 1976 (l* a* b*) uniform colour space and colour-difference formula. Journal of the Society of Dyers and Colourists, 92(9):338–341, 1976. URL: http://dx.doi.org/10.1111/j.1478-4408.1976.tb03301.x, doi:10.1111/j.1478-4408.1976.tb03301.x. |
| [Poy12] | Charles Poynton. Digital Video and HD: Algorithms and Interfaces. Morgan Kaufmann Publishers Inc., San Francisco, CA, USA, 2 edition, 2012. ISBN 9780123919267, 9780123919328. |
asCompositeColor¶
A node to composite two RGBA inputs using Porter-Duff [Porter:1984:CDI:800031.808606] compositing operators.
Parameters¶
Color Parameters¶
- Source Color
- The source color.
- Source Alpha
- The source alpha channel.
- Destination Color
- The destination color.
- Destination Alpha
- The destination alpha channel.
- Composite Mode
The composite operator [1] to use. It can take the following values
- Source
- Destination
- Over
- Under
- In
- Mask
- Out
- Stencil
- Atop
- Dst-Atop
- Xor
- Matte
See also
Merging and Transformation of Raster Images for Cartoon Animation [Wallace:1981:MTR:965161.806813] and the W3.org webpage for a detailed view on compositing algebra in general.
- Clamp Output
- Checking this checkbox will clamp the output into the [0,1] range.
Outputs¶
- Output Color
- The composited color.
- Output Alpha
- The alpha with the result of the compositing operation.
Footnotes
| [1] | The original Porter-Duff paper (PDF file) can be found here. |
References
| [PD84] | Thomas Porter and Tom Duff. Compositing digital images. In Proceedings of the 11th Annual Conference on Computer Graphics and Interactive Techniques, SIGGRAPH ‘84, 253–259. New York, NY, USA, 1984. ACM. URL: http://doi.acm.org/10.1145/800031.808606, doi:10.1145/800031.808606. |
| [Wal81] | Bruce A. Wallace. Merging and transformation of raster images for cartoon animation. SIGGRAPH Comput. Graph., 15(3):253–262, August 1981. URL: http://doi.acm.org/10.1145/965161.806813, doi:10.1145/965161.806813. |
asCreateMask¶
A node that allows the user to create a greyscale mask of a input color or texture.
Parameters¶
Color Parameters¶
- Input Color
- The color used to create the mask from. It’s expected to be scene-linear.
- Input Alpha
- The alpha channel of the color used to create the mask from.
- Threshold Channel
The channel to use when applying a threshold in order to build a mask. It can be one of
- Threshold Value
- The threshold value to apply to the channel chosen.
- Threshold Function
The function to use for the threshold. It can be one of
- Threshold Contrast
- The contrast to apply when the function is Double Circled Seat (a contrast flattening curve) or Double Circled Sigmoid (a contrast increasing curve).
- Threshold Lower Bound
- The lower bound for the smoothstep, smootherstep and smootheststep functions.
- Threshold Upper Bound
- The upper bound for the smoothstep, smootherstep and smootheststep functions.
Screenshots¶
Some examples showing some of the masks created with the modes outlined above.
Footnotes
| [1] | CIELAB or CIE 1976 L*a*b* color space. |
| [2] | For this this assumes the input color is using the ITU-R BT.709/Rec.709 RGB primaries. Once support for working or rendering space using other primaries other than Rec.709 is added to appleseed, this will be extended. |
| [3] | A contrast flattening function, see Double Circled Seat function. |
| [4] | A contrast increasing function, see Double Circled Sigmoid function. |
| [5] | A smoother smoothstep function, with 0 first and second derivatives at x=0 and x=1. |
| [6] | Like smootherstep, but with 0 third derivatives at x=0, and x=1. |
asDoubleShade¶
A node that allows the user to set a color for forward facing faces and for back facing faces.
Parameters¶
Color Parameters¶
- Front Color
- The color or input for the front facing geometry.
- Back Color
- The color or input for the back facing geometry.
Outputs¶
- Output Color
- The resulting color.
asFalloffAngle¶
A node that takes as input two vectors, and returns a smoothly interpolated value between a user set lower and upper bounds for the angle between them.
Parameters¶
Input Parameters¶
- Vector 1
- The first input vector to consider.
- Normalize Input 1
- If the input vector is not unit length, enabling this checkbox will normalize it.
- Vector 2
- The second input vector to consider.
- Normalize Input 2
- If the input vector is not unit length, enabling this checkbox will normalize it.
Interpolation Parameters¶
- Smoothstep Lower Bound
- The lower bound for the smooth interpolation for the angle between the two input vectors.
- Smoothstep Upper Bound
- The upper bound for the smooth interpolation for the angle between the two input vectors.
- Smoothstep Function
The smooth interpolation [1] function to use, it can be one of
- Smooth Step
- Smoother Step
- Smoothest Step
Outputs¶
- Result
- The smoothly interpolated value.
See also
The wikipedia page on smoothstep for more information.
Footnotes
| [1] | Where smootherstep has 0 first and second derivatives, and smootheststep has 0 third derivatives as well. |
asFresnel¶
A node that gives the user the reflection amount due to a viewer Fresnel term for dielectrics or conductors.
Parameters¶
Fresnel Parameters¶
- Fresnel Type
The type of Fresnel function to use. It can be one for dielectric [1] materials, or for conductors [2], with a physically based or an artist friendly [Gulbrandsen2014Fresnel] parameterization. The values it can take are therefore
- Simple Dielectric
- Artist Friendly
- Physically Based
Hint
You can find physically based values for the complex index of refraction [3] in literature or in online resources such as this RefractiveIndex.Info or LuxPop.com.
- Index Of Refraction
- The (monochromatic) absolute index of refraction for a dielectric, considered only when Fresnel Type is set to Simple Dielectric.
- Facing Tint
- The R,G,B reflectance at normal or facing incidence for a conductor Fresnel. Considered only when the Fresnel Type parameter is set to Artist Friendly.
- Edge Tint
- The R,G,B reflectance at edge or grazing incidence for Fresnel. Considered only when the Fresnel Type parameter is set to Artist Friendly.
- Complex IOR
- The R,G,B index of refraction for the conductor Fresnel [4]. Considered only when in Physically Based mode.
- Extinction Coefficient
- The R,G,B extinction coefficient for the conductor Fresnel [5]. Considered only when in Physically Based mode.
Warning
In order to be physically correct, the Fresnel term would need to provide the amount of light reflected off the surface of the object, but the object’s surface might be described (and typically is) by a statistical distribution of normal vectors. Therefore, the correct Fresnel term would depend on this distribution’s microfacet normal, and subsequently on the surface roughness.
This node however does not provide the Fresnel reflection amount off a microfacet normal, but from the true surface normal, a viewer Fresnel term. This is provided for creative freedom (i.e: creative blending of materials with asBlendShader node.
Globals Parameters¶
- Surface Normal
- The unit length, world space shading normal. You can use the bump normal here as well, as long as it’s normalized and in world space.
- Viewer Vector
- The unit length, world space vector pointing from the eye position to the surface point P being shaded.
Outputs¶
- Output Color
- The output RGB Fresnel reflection amount.
- Output Alpha
- The output dielectric Fresnel amount when Fresnel Type is set to Simple Dielectric, or the luminance [6] of the Output Color when set to the other modes.
Footnotes
| [1] | See dielectric definition and Fresnel Equations for details. |
| [2] | See conductor definition for details. |
| [3] | Complex index of refraction, where the real part  is the index of refraction and describes the phase velocity of the wave, and the imaginary part  is the extinction coefficient and indicates the amount of attenuation when the electro-magnetic wave propagates through the material.
See Complex refractive index for more details. |
| [4] | More precisely the real part of the complex index of refraction of the conductor. |
| [5] | More precisely, the imaginary part of the complex index of refraction for a conductor. |
| [6] | For now, the luminance is set to use the ITU-R BT.709/Rec.709 Y coefficients, since that is the working space appleseed is using. In the future, this will automatically reflect the choice of working or rendering space chosen by the user. |
References
| [Gul14] | Ole Gulbrandsen. Artist friendly metallic fresnel. Journal of Computer Graphics Techniques (JCGT), 3(4):64–72, December 2014. URL: http://jcgt.org/published/0003/04/03/. |
asGlobals¶
A node that exposes the OSL [1] global variables to the user, and the appleseed specific global variables as well.
Parameters¶
This node has no input parameters.
Outputs¶
- Surface Position
- The surface point P in world space.
- Reference Position
- The surface point Pref of a reference or pose mesh, in world space.
- Light Point Position
- The position in the light source, Ps, in world space.
- Shading Normal
- The surface normal N in world space, not necessarily normalized.
- Reference Normal
- The surface normal Nref of a reference or pose mesh, in world space.
- Geometric Normal
- The true geometric normal Ng in world space, not necessarily normalized.
- Viewer Vector
- The vector I pointing from the eye position into the surface point being shaded, unit length.
- Bitangent Vector
- The bitangent or binormal vector Bn, unit length.
- Tangent Vector
- The tangent vector Tn, unit length.
- Shutter Time
- The time global variable, denoting shutter time.
- Time Amount
- The amount of time dtime covered by the shading sample.
- dP/dtime
- Derivative of P in regard to time, or how P changes per unit time.
- U Coordinate
- Texture coordinate u.
- V Coordinate
- Texture coordinate v.
- UV Coordinates
- A float array containing both the u and v coordinates, sometimes required for some applications that expect this specific data type.
- dN/du
- The global variable dNdu is a appleseed specific global variable, and denotes the change of N in regard to u.
- dN/dv
- The global variable dNdv is a appleseed specific global variable, and denotes the change of N in regard to v.
- dP/du
- The global variable dPdu, denoting the rate of change or partial derivative of P in regard to u.
- dP/dv
- The global variable dPdv, denoting the rate of change or partial derivative of P in regard to v.
- dP/dx
- The rate of change or partial derivative of P in regard to x, or
Dx(P). - dP/dy
- The rate of change or partial derivative of P in regard to y, or
Dy(P). - dP/dz
- The rate of change or partial derivative of P in regard to z, or
Dz(P).
Attention
Some of the global variables exposed are specific to appleseed, hence shaders using these variables will not be entirely portable, unless the target renderers have some measure of equivalency.
Footnotes
| [1] | OSL or Open Shading Language. |
asIdManifold¶
A utility node that generates a integer hash, a color ID, and a greyscale ID from the input geometry, based on a number of user-set criteria. Coupled with color variation or randomization nodes, this allows the user to shade effortlessly large scenes with natural looking variation.
Parameters¶
Manifold Parameters¶
- Manifold Type
The criteria to use when generating the outputs. It can create the randomization outputs based on the object, instance or assembly names or their IDs, and based on string matching via regular expressions [1]. It takes the following values
- Object Name
- Object Instance Name
- Assembly Name
- Assembly Instance Name
- Face ID
- String Prefix
- String Suffix
- Find String [2]
String Parameters¶
- Expression
- The string expression to search for in the object or instance name. This string can be a regular expression.
- Domain
The domain of the input for the string matching with the Expression parameter. It can take the following values
- Object Name
- Object Instance Name
- Assembly Name
- Assembly Instance Name
- Seed
- The seed [3] to use when generating the randomization outputs.
Output Mode Parameters¶
- Output Mode
The type of outputs created with the node. It can take the values
- Hash Only
- Hash & Greyscale Value
- Hash, Greyscale & Color ID
Outputs¶
- Output Hash
- The resulting integer hash.
- Output ID
- The resulting color ID.
- Output Greyscale
- The resulting greyscale ID.
Footnotes
| [1] | Regular expressions, or regex. If you’re unfamiliar with it, it allows the creation of complex patterns for string and substring matching. You can validate your expressions here at regex101. |
| [2] | This mode tries to match the pattern anywhere in the string, while the two previous modes (string suffix and string prefix) try to match the beginning and the end of the string that was passed. |
| [3] | A number used to initialize a pseudo random number generator, to allow some degree of determinism in a system. See random seed for more information. |
asLuminance¶
A node that returns the luminance of a color, respecting the color space definitions (that is, the chromaticity coordinates of the primaries and the white point).
Parameters¶
Color Attributes¶
- Input Color
- The color being evaluated
Color Space¶
- Derive From Maya CMS
- Uses the render space definitions from Maya’s synColor. This will set the chromaticity coordinates of the RGB primaries, and the white point, standardized in the color space chosen in the synColor configuration. When this is not set, the user must set the appropriate options matching its choice of rendering/working space.
Important
appleseed and appleseed-maya don’t yet take OpenColorIO into account, so this parameter considers the working space definitions from synColor only. If you wish to use OCIO you must set the appropriate color space and white point settings. The default is (scene-linear) sRGB/Rec.709 primaries, with D65 whitepoint.
- Input Color Space
The color space chosen as render/working space. It allows the user to choose one of the following
- ACES 2065-1 AP0 (D60) [7289895]
- ACEScg AP1 (D60) [Duiker:2015:ACC:2791261.2791273]
- Rec.2020 (D65) [6784055]
- DCI-P3 (DCI) [7290729]
- sRGB/Rec.709 (D65)
- Chromaticity Coordinates
Hint
When choosing Chromaticity Coordinates, the user must enter the xy chromaticity coordinates of the R,G,B primaries, and must choose the whitepoint, either in the form of one of the available standard illuminants, in the xy chromacity coordinates of the whitepoint, or via the correlated color temperature.
- R xy Coordinates
- The xy chromaticity coordinates of the red primary.
- G xy Coordinates
- The xy chromaticity coordinates of the green primary.
- B xy Coordinates
- The xy chromaticity coordinates of the blue primary.
- White Point
The white point definition, which can be one of the following options:
- Standard Illuminant D50
- Standard Illuminant D55
- Standard Illuminant D60
- Standard Illuminant D65
- Standard Illuminant D75
- DCI White Point
- White Point E
- Correlated Color Temperature
- White Point Chromaticity Coordinates
- Color Temperature
- The input color temperature value in Kelvin degrees, from 1667K to 25000K.
- W xy Coordinates
- The xy chromacity coordinates of the white point.
Screenshots¶
Some examples of the output luminance of the input color ramp, rendered in (scene linear) Rec.709 space, standard illuminant D65, with different color spaces and whitepoints chosen. The mismatches in color spaces are for illustration purposes. If the settings cannot be derived automatically from your DCC application, then the choice of color space should match your choice or render/working space.
References
| [DFD+15] | Haarm-Pieter Duiker, Alexander Forsythe, Scott Dyer, Ray Feeney, Will McCown, Jim Houston, Andy Maltz, and Doug Walker. Acescg: a common color encoding for visual effects applications. In Proceedings of the 2015 Symposium on Digital Production, DigiPro ‘15, 53–53. New York, NY, USA, 2015. ACM. URL: http://doi.acm.org/10.1145/2791261.2791273, doi:10.1145/2791261.2791273. |
| [Ini11] | Digital Cinema Initiatives. Rp 431-2:2011 - smpte recommended practice - d-cinema quality #x2014; reference projector and environment. SMPTE RP 431-2:2011, pages 1–14, April 2011. doi:10.5594/SMPTE.RP431-2.2011. |
| [oMPAS12] | The Academy of Motion Picture Arts and Sciences. St 2065-1:2012 - smpte standard - academy color encoding specification (aces). ST 2065-1:2012, pages 1–23, April 2012. doi:10.5594/SMPTE.ST2065-1.2012. |
| [SCW14] | M. Sugawara, S. Y. Choi, and D. Wood. Ultra-high-definition television (rec. itu-r bt.2020): a generational leap in the evolution of television [standards in a nutshell]. IEEE Signal Processing Magazine, 31(3):170–174, May 2014. doi:10.1109/MSP.2014.2302331. |
asManifold2D¶
A node that allows the user to transform UV coordinates, compute the filter sizes, define tiling, behavior outside of UV frame area, and more.
Parameters¶
UV Coordinates¶
- UV Coordinates
- The input UV coordinates to transform. If not set, they default to the U and V global primitive variables.
- UV Filter Size
- Filter widths for the input UV coordinates. If not set, they might be computed if required further below in the shader.
- Bypass UV
- Bypass UV transformations, but still allowing you to compute the UV filter widths if required.
- Compute Filters
- Flag that toggles computing the UV coordinates filter widths.
UV Frame¶
- Scale UV Frame
- Scale the UV frame horizontally and vertically.
- Translate UV Frame
- Translate the UV frame horizontally and vertically.
- Rotate UV Frame
- Rotate the UV frame, where the unrestricted interval [0,1] maps to [0,360] degrees.
- Frame Center
- Set the center of rotation X and Y coordinates.
- Wrap Along U
Set the U wrap mode for values outside the UV frame. These can be:
- Periodic: where you have repeating tiles
- Mirror: where you have mirrored repeating tiles
- Clamp: coordinates clamped to the limits of the UV frame
- Default Color: areas outside the UV frame take the default color set in nodes such as the asTexture node, in the form of its lookup failure color, or specific default color in other 2d texturing nodes. [1]
- Wrap Along V
Set the V wrap mode for values outside the UV frame. These can be:
- Periodic: where you have repeating tiles
- Mirror: where you have mirrored repeating tiles
- Clamp: coordinates clamped to the limits of the UV frame
- Default Color: areas outside the UV frame take the default color set in nodes such as the asTexture node, in the form of its lookup failure color, or specific default color in other 2d texturing nodes.
Transform Parameters¶
- UV Tiles
- The number of UV tiles along U and V directions.
- Offset Tiles
- An offset to apply to the tiles, along the U and V directions.
- Rotate Tiles
- Rotate tiles along a center of rotation, where the input values on the unrestricted interval [0,1] map to [0,360] degrees rotation.
- Tiles Center
- Center of rotation for tiles rotation.
- Tiles Coverage
- Defines how much of the UV frame is covered by the texture.
Tile Parameters¶
- Mirror U
- Mirror the tiles along the U direction.
- Mirror V
- Mirror the tiles along the V direction.
- Wrap U
- Wrap the tiles along the U direction.
- Wrap V
- Wrap the tiles along the V direction.
- Stagger UV
- Similar to Maya’s stagger, it offsets alternate rows of tiles by half the tile width, creating a brickwall kind of effect.
- Swap UV
- Swap the U and V coordinates.
Noise¶
- Distort UV
- Applies a signed Perlin noise to the input UV coordinates, where the texturing coordinates are the original unmodified UV coordinates scaled by a factor of 15.0 to increase the noise frequency.
Outputs¶
- UV Coords
- The resulting UV coordinates.
- UV Filter Size
- The filter widths for the UV coordinates, either bypassed, or final transformed UV coordinates.
Footnotes
| [1] | In the case of the asTexture node the color used outside the [0,1] UV frame is the lookup failure color. In other nodes, you might have the access in some nodes, to set a specific default color, in a way similar to what Maya does for example. |
References
asRaySwitch¶
A node that returns a specific input color according to the ray type being evaluated by the renderer [Heckbert:1990:ART:97880.97895].
Parameters¶
Color Attributes¶
- Camera Ray Color
- The color that passes through for primary visibility rays, also known as camera rays.
- Light Ray Color
- The color that passes through light rays, involved in light emitting surfaces and light sources (via EDF or emittance distribution functions). This is also used in Bi-Directional Path Tracing [1] and in Stochastic Progressive Photon Mapping [2].
- Shadow Ray Color
- The color that passes through for shadow rays, that compute the visibility between two points.
- Transparency Ray Color
- The color that passes through for rays of type transparency, for matte holdouts, and when the transparency closure is evaluated.
- Diffuse Ray Color
- The color that passes through for rays of type diffuse, typically involved in indirect diffuse lighting.
- Glossy Ray Color
- The color that passes through for glossy rays, typically involved in glossy indirect specular lighting, such as blurry/soft reflections or refractions.
- Specular Ray Color
- The color that passes through for specular rays, typically involved in the calculation of perfect mirror reflective or refractive surfaces.
- Subsurface Ray Color
- The color that passes through for rays of type subsurface, typically involved in lighting calculations of BSSRDFs.
Outputs¶
- Output Color
- The color that passed passed through for the specific ray type.
Footnotes
| [1] | BDPT for short, see [Veach:PhD] |
| [2] | SPPM for short, see [Hachisuka:2009:SPP:1618452.1618487] |
References
| [HJ09] | Toshiya Hachisuka and Henrik Wann Jensen. Stochastic progressive photon mapping. ACM Trans. Graph., 28(5):141:1–141:8, December 2009. URL: http://doi.acm.org/10.1145/1618452.1618487, doi:10.1145/1618452.1618487. |
| [Hec90] | Paul S. Heckbert. Adaptive radiosity textures for bidirectional ray tracing. SIGGRAPH Comput. Graph., 24(4):145–154, September 1990. URL: http://doi.acm.org/10.1145/97880.97895, doi:10.1145/97880.97895. |
| [Vea97] | Eric Veach. Robust Monte Carlo Methods for Light Transport Simulation. PhD thesis, Stanford University, Stanford, CA, USA, 1997. AAI9837162. |
asSpaceTransform¶
A node meant to transform an input point, normal, or vector, from a coordinate system into another.
Parameters¶
Input Parameters¶
- Point to Transform
- An point like variable to transform.
- Normal to Transform
- A normal like variable to transform.
- Vector to Transform
- A vector like variable to transform.
Space Parameters¶
- From Space
The origin coordinate system. It can be one of
- To Space
The destination coordinate system. It can be one of
- common
- object
- shader
- world
- camera
- screen
- raster
- NDC
- Normalize Output Vectors
- When the input to transform is either of vector type or of normal type, this parameter will make sure the resulting transformed vector or normal are of unit length.
See also
Outputs¶
- Transformed Point
- The transformed input point.
- Transformed Normal
- The transformed input normal, optionally normalized.
- Transformed Vector
- The transformed input vector, optionally normalized.
- Transform Matrix
- The transformation matrix that transforms from From Space to To Space.
Footnotes
| [1] | The common coordinate system is the OSL equivalent of RSL’s current coordinate system and is the coordinate system in which all values start and the one in which lighting calculations are performed. This is a renderer specific coordinate system. In appleseed this is equivalent to the world coordinate system. |
| [2] | The object coordinate system refers to the local coordinate system of the geometry currently shaded. |
| [3] | The shader coordinate system, refers to the coordinate system active by the time of the shader instantiation. |
| [4] | The world coordinate system is the world coordinate system of the scene. |
| [5] | The camera coordinate system refers to the coordinate system with its origin at the center of the camera lens, the x axis pointing right, the y axis pointing up, and the z axis pointing into the screen. |
| [6] | The screen coordinate system refers to the coordinate system of the camera’s image plane after the perspective transformation, if any, with the origin looking along the z axis of the camera coordinate system. |
| [7] | The raster coordinate system refers to the 2D coordinate system with origin at the upper left corner of the image, and xy resolution at the bottom right corner of the image. |
| [8] | The NDC coordinate system, or Normalized Device Coordinates, refers to the coordinate system with origin at the upper left corner of the image, and [1,1] at the xy coordinates of the bottom right of the image. |
asSwitchTexture¶
A node that switches the output texture from a list of 8 inputs, based on object or instance IDs, names, or string patterns, facilitating the creation of automatic variation in large scenes.
Parameters¶
Color Parameters¶
- Input Color 0
- The first color in the list of colors or textures to evaluate.
(…)
Note
The subsequent inputs follow exactly the same structure and parameterization.
- Input Color 7
- The last color in the list of colors or textures to evaluate.
- Cycle Mode
- When cycling through the list of colors or textures, if the index goes outside the list bounds, then one has the choice to cycle back to the beginning of the list, or if to clamp to the list size.
Manifold Parameters¶
- Manifold Type
The type of manifold to use in order to determine which lookup to do in the list of colors or textures. It can be one of the following
- Object Name
- Object Instance Name
- Assembly Name
- Assembly Instance Name
- Face ID
- String Prefix
- String Suffix
- Find String
Outputs¶
- Output Color
- The resulting color.
Footnotes
| [1] | Regular expressions, or regex. If you’re unfamiliar with it, it allows the creation of complex patterns for string and substring matching. You can validate your expressions here at regex101. |
| [2] | A number used to initialize a pseudo random number generator, to allow some degree of determinism in a system. See random seed for more information. |
asSwizzle¶
A node that rearranges the elements of an input color+alpha, or vector.
Parameters¶
Color¶
- Input Color
- The color to rearrange.
- Input Alpha
- The alpha channel for the final RGBA output.
- Red Channel
- What RGBA channel to use as the new Red channel.
- Green Channel
- What RGBA channel to use as the new Green channel.
- Blue Channel
- What RGBA channel to use as the new Blue channel.
- Alpha Channel
- What RGBA channel to use as the new Alpha channel.
- Invert Red
- Inverts the new Red channel. It assumes the color was in [0,1] range.
- Invert Green
- Inverts the new Green channel. It assumes the color was in [0,1] range.
- Invert Blue
- Inverts the new Blue channel. It assumes the color was in [0,1] range.
- Invert Alpha
- Inverts the new Alpha channel. It assumes the color was in [0,1] range.
Vector¶
- Vector Type
A vector type variable, it can be one of types
- normal
- vector
- point
- X Component
- What XYZ component to use as the new X component.
- Y Component
- What XYZ component to use as the new Y component.
- Z Component
- What XYZ component to use as the new Z component.
- Invert X
- Inverts the new X component.
- Invert Y
- Inverts the new Y component.
- Invert Z
- Inverts the new Z component.
Outputs¶
- Output Color
- The rearranged color.
- Output Alpha
- The rearranged alpha.
- Output Vector
- The rearranged vector.
asTextureInfo¶
A node providing the user with a number of potentially useful information for the input texture. Notice that the input texture can be any texture, a 2D or 3D texture. The list of information queried might be extended to include appleseed specific metadata.
Outputs¶
- Average Color
- The average color of the first 3 channels of the texture file.
- Average Alpha
- The average value of the channel with the A name in the texture file, if it exists.
- Resolution
- A vector containing the X and Y resolution in its first two components, or the X, Y and Z resolution in the case of input 3D texture file.
- Channels
- The total number of channels in the input texture file.
- Subimages
- The number of subimages in the texture file. In the EXR case, this refers to the number of additional channels.
- Texture Type
Returns the type of the texture file, with the following strings according to the input type
- Plain Texture
- Shadow
- Environment
- Volume Texture
- Texture Format
The texture format of the input file, differentiating between the format of the fundamental texture types. The return strings can take the following values
- Plain Texture
- Shadow
- CubeFace Shadow
- Volume Shadow
- CubeFace Environment
- LatLong Environment
- Volume Texture
- Data Window Minimum
- A vector containing the minimum X and Y values of the pixel data window of the input texture, in the case of a 2D texture file. And the minimum X, Y and Z values of the pixel data window in the case of a 3D texture file.
- Data Window Maximum
- A vector containing the maximum X and Y values of the pixel data window of the input texture, in the case of a 2D texture file. And the maximum X, Y and Z values of the pixel data window in the case of a 3D texture file.
- Display Window Minimum
- A vector containing the minimum X and Y values of the full window of the image, in the case of a 2D texture file, and the minimum X, Y and Z values in the case of a 3D texture file.
- Display Window Maximum
- A vector containing the maximum X and Y values of the full window of the image, in the case of a 2D texture file, and the maximum X, Y and Z values in the case of a 3D texture file.
- World To Camera Matrix
- When the input texture is a rendered image, this parameter provides the world to camera transformation matrix used.
- World To Screen Matrix
- When the input texture is a rendered image, this parameter provides the matrix that transforms points from world space into screen space - a 2D coordinate system where the x and y values are in [-1,1] range.
See also
The Open Shading Language documentation at github.
asTriplanar¶
A triplanar projection shader, allowing individual texture(s) to be projected along the object’s X, Y and Z axis, and blended. It can be used to blend colors or tangent space normal maps.
Parameters¶
Projection¶
- Blend Mode
Allowing the user to choose between blending colors, or blending tangent space normal maps [1]. It can take the values
- Color
- Tangent Normal
- Blend Softness
- Controls the transition softness between the projections, with higher values having a faded and very wide transition, and lower values having sharper well defined transition areas.
- Surface Point
- The point being shaded.
- Coordinate Space
The coordinate system to use, it can be one of
- Object Space
- World Space
X Axis¶
- Solid Color
- Solid color for the X axis projection.
- Texture Filename
- The texture to use for the X axis projection.
Tip
Nothing prevents the user from using the same texture for all axis projections.
- Horizontal Frequency
- The horizontal frequency of the texture for the X axis projection.
- Vertical Frequency
- The vertical frequency of the texture for the X axis projection.
- Horizontal Offset
- The horizontal offset of the texture for the X axis projection.
- Vertical Offset
- The vertical offset of the texture for the X axis projection.
- Rotation
- The rotation angle for the X axis projection, in degrees, between -360 and 360 degrees.
- S Wrap Mode
The texture wrapping mode along the s texture coordinate for the X axis projection. It can be one of
- Default
- Black
- Periodic
- Clamp
- Mirror
- T Wrap Mode
The texture wrapping mode along the t texture coordinate for the X axis projection. It can be one of
- Default
- Black
- Periodic
- Clamp
- Mirror
- S Flip
- A flag that toggles the mirroring of the projected texture along the s texture coordinate.
- T Flip
- A flag that toggles the mirroring of the projected texture along the t texture coordinate.
- Input Transfer Function
Applies an Electro-Optical Transfer Function, or EOTF, to the input texture, linearizing it. It can take the following values
- None/Raw
- sRGB
- Rec.709
- Gamma 2.2
- Gamma 2.4
- Gamma 2.6 (DCI)
- Rec.1886 [2]
- Rec.2020
- RGB Primaries
It allows the user to set the RGB primaries that define the color space of the input texture, and can take the following values
Y and Z axis¶
(…)
Attention
The Y and Z axis projection parameters follow exactly the same structure as the X axis projection parameters and are omitted here for brevity.
Randomization¶
- Randomization
- Allows the user to add variation to the triplanar node by randomly rotating the projection axis frame, with a value of 0.0 meaning no variation at all, and a value of 1.0 allowing rotations between -360.0 and 360.0 degrees.
- Manifold
- An integer hash, usually provided by the asIdManifold node. Lacking such a connection, it defaults to adding variation based on the object’s assembly instance name.
Bump Mapping¶
- Bump Mapping
- The unit length bumped shading normal.
Color Management¶
- Enable CMS
- Toggles the color management options on or off.
- Rendering RGB Primaries
It allows the user to set the RGB primaries of the rendering or working space, and it should match the choice of rendering/working space of the renderer. It can take the following values
- sRGB/Rec.709
- Rec.2020
- DCI-P3
- ACES
- ACEScg
Outputs¶
- Output Color
- The color resulting from the Features Mode choice.
- Output Alpha
- The alpha resulting from the Features Mode choice, usually luminance of the color only.
- Output Normal
- The resulting blended tangent space normal maps as unit length normals in world space when the Blend Mode is set to Tangent Normal.
Footnotes
| [1] | See blending in detail for details on blending tangent space normals using several methods. This node uses the Reoriented Normal Mapping (or RNM) blend method to blend tangent space normals when Blend Mode is set to Tangent Normal. |
| [2] | See ITU-R BT.1886 recommendation for details on the electro-optical transfer function. |
| [3] | Because it makes no sense whatsoever to use colorimetry on non-color information or data, such as normal maps, or Z depth, motion vectors, and so on. |
| [4] | sRGB shares the same CIE xy chromaticity coordinates with ITU-R BT.709/Rec.709 , hence this node refers to the RGB primaries shared by these two color spaces as sRGB/Rec.709. |
| [5] | See encoding characteristics of AdobeRGB specification. |
References
| [DFD+15] | Haarm-Pieter Duiker, Alexander Forsythe, Scott Dyer, Ray Feeney, Will McCown, Jim Houston, Andy Maltz, and Doug Walker. Acescg: a common color encoding for visual effects applications. In Proceedings of the 2015 Symposium on Digital Production, DigiPro ‘15, 53–53. New York, NY, USA, 2015. ACM. URL: http://doi.acm.org/10.1145/2791261.2791273, doi:10.1145/2791261.2791273. |
| [Ini11] | Digital Cinema Initiatives. Rp 431-2:2011 - smpte recommended practice - d-cinema quality #x2014; reference projector and environment. SMPTE RP 431-2:2011, pages 1–14, April 2011. doi:10.5594/SMPTE.RP431-2.2011. |
| [oMPAS12] | The Academy of Motion Picture Arts and Sciences. St 2065-1:2012 - smpte standard - academy color encoding specification (aces). ST 2065-1:2012, pages 1–23, April 2012. doi:10.5594/SMPTE.ST2065-1.2012. |
| [SCW14] | M. Sugawara, S. Y. Choi, and D. Wood. Ultra-high-definition television (rec. itu-r bt.2020): a generational leap in the evolution of television [standards in a nutshell]. IEEE Signal Processing Magazine, 31(3):170–174, May 2014. doi:10.1109/MSP.2014.2302331. |
asVaryColor¶
A color variation utility node, meant to automate the coloring and shading of large numbers of objects in a scene based on user-set criteria such as object or instance names or IDs.
Parameters¶
Color Parameters¶
- Input Color
- The original input color.
- Color Mode
How to apply the manifold color to the input color. The manifold generated value can be added to the input color, it can modulate the input color, or it can bypass it completely, via the parameters
- Add
- Scale
- Override
Manifold Parameters¶
- Manifold Type
The manifold type to use for the variation. It can take the following values
- Object Name
- Object Instance Name
- Assembly Name
- Assembly Instance Name
- Face ID
- String Prefix
- String Suffix
- Find String
String Parameters¶
- Expression
- When Manifold Type is set to String Prefix, String Suffix or Find String, the expression can be a regex [1] expression defining the pattern to search in the expression domain.
- Domain
The domain to search the expression for. The domains can take the values
- Object Name
- Object Instance Name
- Assembly Name
- Assembly Instance Name
- Seed
- An extra seed to provide some measure of determinism in the resulting colors.
Variation Parameters¶
- Variation Mode
This parameter controls what exactly is going to be randomized or vary, according to the user-set options outlined earlier. One can vary the individual (and/or full) components of the input color in HSV [2] space, in RGB or in CIELAB [3] space. Accordingly this parameter takes the following values
- HSV
- RGB
- CIE L*a*b* 1976
HSV Variation Parameters¶
- Vary Hue
- The extent or scaling factor of the hue variation.
- Vary Saturation
- The extent or scaling factor of the saturation variation.
- Vary Value
- The extent or scaling factor of the value variation.
RGB Variation Parameters¶
- Vary Red
- The extent or scaling factor of the variation of the red channel.
- Vary Green
- The extent or scaling factor of the variation of the green channel.
- Vary Blue
- The extent or scaling factor of the variation of the blue channel.
CIELAB Variation Parameters¶
- Vary L\*
- The extent or scaling factor of the variation of the lightness or L\* channel.
- Vary a\*
- The extent or scaling factor of the variation of the a\* channel.
- Vary b\*
- The extent or scaling factor of the variation of the b\* channel.
Outputs¶
- Output Color
- The resulting randomized color.
- Output Hash
- An integer hash ID.
- Output ID
- A color ID.
- Output Greyscale
- A greyscale ID.
Footnotes
| [1] | Regular expressions, or regex. If you’re unfamiliar with it, it allows the creation of complex patterns for string and substring matching. You can validate your expressions here at regex101. |
| [2] | A different color representation based on hue, saturation and value. See HSV color space for more details. |
| [3] | Also known as Lab color space, but it’s in fact referring to CIE 1976 L*a*b* color space, or CIELAB. See CIELAB color space for more details. |
Custom appleseed shaders¶
These shaders are meant to either replace some of Maya’s functionality that wasn’t possible to implement directly in OSL, or to provide functionality that is inexistent and we feel might be useful to the end user.
Texture Nodes¶
Color Utilities¶
General Utilities¶
About¶
appleseed-maya is an open-source, MIT-licensed multi-platform [1] renderer integration plugin for Autodesk® Maya® 2017 and later.
Footnotes
| [1] | Besides Linux, macOS and Windows, appleseed was known to build and run on the Raspberry Pi3, and IBM POWER8. |