tinyusdz/models/mtlx-normalmap-sphere.usda

#usda 1.0
(
    doc = "MaterialX Normal Map Test - Sphere Geometry"
    metersPerUnit = 1
    upAxis = "Y"
    defaultPrim = "World"
)

def Xform "World"
{
    def Sphere "NormalMapSphere" (
        prepend apiSchemas = ["MaterialBindingAPI"]
    )
    {
        double radius = 1.0
        rel material:binding = </World/_materials/NormalMapMaterial>
    }

    def Scope "_materials"
    {
        def Material "NormalMapMaterial" (
            prepend apiSchemas = ["MaterialXConfigAPI"]
        )
        {
            string config:mtlx:version = "1.39"
            token outputs:mtlx:surface.connect = </World/_materials/NormalMapMaterial/OpenPBRShader.outputs:surface>
            token outputs:surface.connect = </World/_materials/NormalMapMaterial/FallbackShader.outputs:surface>

            # OpenPBR Surface Shader with normal map
            def Shader "OpenPBRShader"
            {
                uniform token info:id = "ND_open_pbr_surface_surfaceshader"
                color3f inputs:base_color = (0.7, 0.8, 0.9)
                float inputs:base_weight = 1.0
                float inputs:base_metalness = 0.0
                float inputs:base_diffuse_roughness = 0.0
                float inputs:specular_weight = 1.0
                float inputs:specular_roughness = 0.25
                float inputs:specular_ior = 1.5
                float3 inputs:geometry_normal.connect = </World/_materials/NormalMapMaterial/NodeGraph.outputs:normal_out>
                float3 inputs:geometry_tangent.connect = </World/_materials/NormalMapMaterial/NodeGraph.outputs:tangent_out>
                token outputs:surface
            }

            # Fallback UsdPreviewSurface
            def Shader "FallbackShader"
            {
                uniform token info:id = "UsdPreviewSurface"
                color3f inputs:diffuseColor = (0.7, 0.8, 0.9)
                float inputs:roughness = 0.25
                float inputs:metallic = 0.0
                normal3f inputs:normal.connect = </World/_materials/NormalMapMaterial/FallbackNormalTexture.outputs:rgb>
                token outputs:surface
            }

            def Shader "FallbackNormalTexture"
            {
                uniform token info:id = "UsdUVTexture"
                asset inputs:file = @./textures/normalmap-gradient.png@ (
                    colorSpace = "raw"
                )
                token inputs:sourceColorSpace = "raw"
                float2 inputs:st.connect = </World/_materials/NormalMapMaterial/FallbackTexCoord.outputs:result>
                float4 inputs:scale = (2.0, 2.0, 2.0, 1.0)
                float4 inputs:bias = (-1.0, -1.0, -1.0, 0.0)
                float3 outputs:rgb
            }

            def Shader "FallbackTexCoord"
            {
                uniform token info:id = "UsdPrimvarReader_float2"
                string inputs:varname = "st"
                float2 outputs:result
            }

            # MaterialX NodeGraph for normal/tangent handling
            def NodeGraph "NodeGraph"
            {
                float3 outputs:normal_out.connect = </World/_materials/NormalMapMaterial/NodeGraph/NormalMapNode.outputs:out>
                float3 outputs:tangent_out.connect = </World/_materials/NormalMapMaterial/NodeGraph/TangentNormalize.outputs:out>

                # Read UV coordinates
                def Shader "TexCoord"
                {
                    uniform token info:id = "ND_texcoord_vector2"
                    int inputs:index = 0
                    float2 outputs:out
                }

                # Load normal map texture as vector3
                def Shader "NormalMapTexture"
                {
                    uniform token info:id = "ND_image_vector3"
                    asset inputs:file = @./textures/normalmap-gradient.png@ (
                        colorSpace = "raw"
                    )
                    float2 inputs:texcoord.connect = </World/_materials/NormalMapMaterial/NodeGraph/TexCoord.outputs:out>
                    float3 outputs:out
                }

                # Convert tangent space normal to world space
                def Shader "NormalMapNode"
                {
                    uniform token info:id = "ND_normalmap_float"
                    float3 inputs:in.connect = </World/_materials/NormalMapMaterial/NodeGraph/NormalMapTexture.outputs:out>
                    float inputs:scale = 1.0
                    float3 outputs:out
                }

                # Get world space tangent
                def Shader "TangentNode"
                {
                    uniform token info:id = "ND_tangent_vector3"
                    string inputs:space = "world"
                    float3 outputs:out
                }

                # Normalize tangent
                def Shader "TangentNormalize"
                {
                    uniform token info:id = "ND_normalize_vector3"
                    float3 inputs:in.connect = </World/_materials/NormalMapMaterial/NodeGraph/TangentNode.outputs:out>
                    float3 outputs:out
                }
            }
        }
    }

    # Lighting
    def DomeLight "EnvLight"
    {
        float inputs:intensity = 1.0
        asset inputs:texture:file = @./textures/env_studio_default.hdr@
    }

    def DistantLight "KeyLight"
    {
        float inputs:intensity = 2.0
        float3 xformOp:rotateXYZ = (-45, 30, 0)
        uniform token[] xformOpOrder = ["xformOp:rotateXYZ"]
    }
}