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.
Color Management¶
- 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. |