https://graphics.pixar.com/usd/docs/UsdPreviewSurface-Proposal.html
- diffuseColor - color3f - (0.18, 0.18, 0.18)
- emissiveColor - color3f - (0.0, 0.0, 0.0)
- useSpeclarWorkflow - int - 0
- 1
- specularColor - color3f - (0.0, 0.0, 0.0)
- 0
- metallic - float - 0.0
- 1
- roughness - float - 0.5
- clearcoat - float - 0.0
- clearcoatRoughness - float 0.01
- opacity - float - 1.0
- opacityThreshold - float - 0.0
- ior - float - 1.5
- normal - normal3f - (0.0, 0.0, 1.0)
- displacement - float - 0.0
- occlusion - float - 1.0
- surface - token
- displacement - token
- file - asset - string
- st - float2 - (0.0, 0.0)
- wrapS - token - useMetadata
- black, clamp, repeat, mirror,
- wrapT - token = useMetadata
- fallback - float4 - (0.0, 0.0, 0.0, 1.0)
- scale - float4 - (1.0, 1.0, 1.0, 1.0)
- bias - float4 - (0.0, 0.0, 0.0, 0.0)
- r, g, b, a
- in - float2 - (0.0, 0.0)
- rotation - float - (0.0)
- counter-clockwise rotation in degrees around the origin
- scale - float2 - (1.0, 1.0)
- translation - float2 (0.0, 0.0)
- result - float2
- Primvar Reader(arbitrary vertex attributes)
- displacement
- Texture transform