RENDERMAN 22 DOCUMENTATION

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In RfM, an LPE can be easily added by right clicking on an LPE name from the built-in LPEs list in RenderMan Controls' Add Channels/Outputsin Render Settings.

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RenderMan for Katana

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Code Block
DisplayChannel "color lpe:CD<L.>"

Built-in LPEs

NameExpression
lpe:diffuse
lpe:CD<L.>
lpe:specularlpe:CS<L.>
lpe:emissionlpe:CO
lpe:indirectdiffuselpe:(C<RD>[DS]+<L.>)|(C<RD>[DS]*O)
lpe:indirectspecularlpe:(C<RS>[DS]+<L.>)|(C<RS>[DS]*O)
lpe:subsurfacelpe:(C<TD>[DS]+<L.>)|(C<TD>[DS]*O)
lpe:refractionlpe:(C<T[S]>[DS]+<L.>)|(C<T[S]>[DS]*O)
lpe:shadowcollectorlpe:shadows;C[<.D'collector'><.S'collector'>]<L.>

Basic LPEs

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For basic workflows, the following LPE are recommended. Note that below we're specifying the DisplayChannel and a name (which can be anything) as opposed to the examples above using a built-in naming scheme. Note that these LPE will collect the light interaction from different lobes of materials and store them in the same AOV. For example: reflections from the Glass Lobe in PxrSurface will be combined with other specular reflections in the direct and indirectSpecular AOVs. This can simplify the outputs for rendering.

 

DisplayChannelExpression
color beauty
color lpe:C[DS]*[<L.>O]
color emissive
color lpe:C[<L.>O]
color directDiffuse
color lpe:C<RD>[<L.>O]
color indirectDiffuse
color lpe:C<RD>[DS]+[<L.>O]
color subsurface
color lpe:C<TD>[DS]*[<L.>O]
color directSpecular
color lpe:C<RS>[<L.>O]
color indirectSpecular
color lpe:C<RS>[DS]+[<L.>O]
color transmissive
color lpe:C<TS>[DS]*[<L.>O]

 

Per-Lobe LPEs

For advanced workflows that want to separate all scattering lobes into separate AOVs, the below LPE are provided. These capture the light interaction for each lobe, direct and indirect, and store them into separate AOVs. This is useful for tweaking individual effects at the cost of added AOVs and image output.

 

DisplayChannelExpression
color directDiffuseLobe
color lpe:CD2[<L.>O]
color indirectDiffuseLobe
color lpe:CD2[DS]+[<L.>O]
color subsurfaceLobe
color lpe:CD3[DS]*[<L.>O]
color directSpecularPrimaryLobe
color lpe:CS2[<L.>O]
color indirectSpecularPrimaryLobe
color lpe:CS2[DS]+[<L.>O]
color directSpecularRoughLobe
color lpe:CS3[<L.>O]
color indirectSpecularRoughLobe
color lpe:CS3[DS]+[<L.>O]
color directSpecularClearcoatLobe
color lpe:CS4[<L.>O]
color indirectSpecularClearcoatLobe
color lpe:CS4[DS]+[<L.>O]
color directSpecularIridescenceLobe
color lpe:CS5[<L.>O]
color indirectSpecularIridescenceLobe
color lpe:CS5[DS]+[<L.>O]
color directSpecularFuzzLobe
color lpe:CS6[<L.>O]
color indirectSpecularFuzzLobe
color lpe:CS6[DS]+[<L.>O]
color transmissiveSingleScatterLobe
color lpe:CS7[DS]*[<L.>O]
color directSpecularGlassLobe
color lpe:C<RS8>[<L.>O]
color indirectSpecularGlassLobe
color lpe:C<RS8>[DS]+[<L.>O]
color transmissiveGlassLobe
color lpe:C<TS8>[DS]*[<L.>O]

 

For objects that have an LPE group called "collector", lpe:shadowcollector collects shadow and lpe:reflection collects reflection. These shadows. This may be useful for creating holdouts.

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Code Block
DisplayChannel "varying color lpe:diffuse_key"
DisplayChannel "varying color lpe:CD<L.'key'>"

Per-Lobe LPEs

Bxdf materials may have more than one diffuse or specular lobe which are summed for D and S, respectively. However, in some situations, it may be desirable to output a specific lobe separately.

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