The UsdPreviewSurface material is part of the USD Preview Surface spec.
The UsdPreviewSurface is meant to model a “modern” physically based surface that strikes a balance between expressiveness and reliable interchange between current day DCC’s and game engines and other real-time rendering clients.
Second specular lobe amount. The color is white.
Roughness for the second specular lobe.
default: [ 0.18, 0.18, 0.18 ]
When using metallic workflow this is interpreted as albedo.
Displacement in the direction of the normal.
default: [ 0, 0, 0 ]
Bind this attribute to a 'ListMap' that contains references to ExtraAovMaps that specify additional outputs that can be assigned to a RenderOutput "light aov" result
Indicates whether material should/should not appear in the refractive cryptomatte layers
Index of Refraction to be used for translucent objects and objects with specular components, including the clearcoat if clearcoat > 0.
label used in material and light aovs
Use 1 for metallic surfaces and 0 for non-metallic. If metallic is 1, then both F0 (reflectivity at 0 degree incidence) and edge F90 reflectivity will simply be the Albedo. If metallic is 0, then Albedo is ignored in the calculation of F0 and F90; F0 is derived from ior via ( (1-ior)/(1+ior) )^2 and F90 is white. In between, we interpolate.
default: [ 0, 0, 1 ]
Expects normal in tangent space [(-1,-1,-1), (1,1,1)]
Ignored by Moonray
When opacity is 1.0 then the geometry is fully opaque, if it is smaller than 1.0 then the geometry is translucent, when it is 0 the geometry is transparent. Note that even a fully transparent object still receives lighting as, for example, perfectly clear glass still has a specular response.
The opacityThreshold input is useful for creating geometric cut-outs based on the opacity input. A value of 0.0 indicates that no masking is applied to the opacity input, while a value greater than 0.0 indicates that rendering of the surface is limited to the areas where the opacity is greater or equal to that value.
The material's place in an order of precedence for overlapping dielectrics. A value of 0 means the priority should be ignored. Materials with lower numbers (higher priority) "override" materials with higher numbers (lower priority). To enable automatic removal of self-overlapping geometry, a non-zero priority must be set on the geometry's material.
Roughness for the specular lobe. The value ranges from 0 to 1, which goes from a perfectly specular surface at 0.0 to maximum roughness of the specular lobe.
default: [ 0, 0, 0 ]
Specular color to be used. This is the color at 0 incidence. Edge color is assumed white. Transition between the two colors according to Schlick fresnel approximation.
0 = “Metalness workflow” (default)
1 = “Specular workflow”
This node can fundamentally operate in two modes : Specular workflow where you provide a texture/value to the 'specularColor' input. Or, Metallic workflow where you provide a texture/value to the 'metallic' input.