Class PreviewSurfaceSample

The following is based on the Pixar specification found here: https://graphics.pixar.com/usd/docs/UsdPreviewSurface-Proposal.html

Inheritance
object
ShaderSample
PreviewSurfaceSample
Inherited Members
Namespace: USD.NET.Unity
Assembly: solution.dll
Syntax
[Serializable]
public class PreviewSurfaceSample : ShaderSample

Constructors

Name Description
PreviewSurfaceSample()

Fields

Name Description
clearcoat

Second specular lobe amount. The color is white.
clearcoatRoughness

Roughness for the second specular lobe.
diffuseColor

When using metallic workflow this is interpreted as albedo.
displacement

Displacement in the direction of the normal.
emissiveColor

Emissive component.
ior

Index of Refraction to be used for translucent objects.
metallic

Use 1 for metallic surfaces and 0 for non-metallic.

  • If metallic is 1.0, then F0(reflectivity at 0 degree incidence) will be derived from ior( (1-ior)/(1+ior) )^2, then multiplied by Albedo; while edge F90 reflectivity will simply be the Albedo. (As an option, you can set ior to 0 such that F0 becomes equal to F90 and thus the Albedo).

  • If metallic is 0.0, then Albedo is ignored; F0 is derived from ior and F90 is white. In between, we interpolate.
normal

Expects normal in tangent space [(-1,-1,-1), (1,1,1)] This means your texture reader implementation should provide data to this node that is properly scaled and ready to be consumed as a tangent space normal.
occlusion

Extra information about the occlusion of different parts of the mesh that this material is applied to. Occlusion only makes sense as a surface-varying signal, and pathtracers will likely choose to ignore it. An occlusion value of 0.0 means the surface point is fully occluded by other parts of the surface, and a value of 1.0 means the surface point is completely unoccluded by other parts of the surface.
opacity

When opacity is 1.0 then the prim is fully opaque, if it is smaller than 1.0 then the prim is translucent, when it is 0 the prim is transparent.
opacityThreshold

The opacityThreshold input is useful for creating geometric cut-outs based on the opacity input.
outputs
roughness

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. This value is usually squared before use with a GGX or Beckmann lobe.
specularColor

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.
useSpecularWorkflow

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. Depending on the 0 or 1 value of this parameter, the following parameters are conditionally enabled.