material-mdl-schema#

Code

VM.MDL.002

Validator

latest+

Compatibility

kit 107.0+

Tags

✅

Summary#

MDL Shaders must standard OpenUSD shader source attributes to ensure compatibility.

Description#

Materials must use the current MDL shader schema format. The old schema format where info:implementationSource = "mdlMaterial" is used with separate module and name attributes is deprecated and should not be used.

Why is it required?#

  • Compatibility issues in applications that support MDL materials with OpenUSD

Examples#

# Invalid: Using deprecated MDL schema format
def Material "mtl_test"
{
    token outputs:surface.connect = </mtl_test/Shader.outputs:out>

    def Shader "Shader"
    {
        uniform token info:implementationSource = "mdlMaterial"  # Deprecated
        custom asset module = @OmniPBR.mdl@  # Old way of specifying MDL module
        custom string name = "OmniPBR"  # Old way of specifying material name
        token outputs:out
    }
}

# Valid: Using current MDL schema format
def Material "mtl_test"
{
    token outputs:surface.connect = </mtl_test/Shader.outputs:out>

    def Shader "Shader"
    {
        uniform token info:implementationSource = "sourceAsset"
        uniform asset info:mdl:sourceAsset = @./OmniPBR.mdl@
        uniform token info:mdl:materialType = "OmniPBR"
        token outputs:out
    }
}

How to comply#

  • Use the “Asset Validator” extension in NVIDIA Omniverse to update existing assets. See Asset Validator for more information.

  • Update to use info:implementationSource = "sourceAsset"

  • Use info:mdl:sourceAsset instead of module

  • Use info:mdl:materialType instead of name

  • Convert any materials using the old schema format

For More Information#