material-mdl-source-asset#

Code

VM.MDL.001

Validator

latest+

Compatibility

open usd

Tags

✅

Summary#

MDL material source assets must be properly referenced and accessible to ensure material loading and rendering.

Description#

MDL material source assets must be properly referenced using the info:mdl:sourceAsset attribute and must be accessible in the expected location. The source asset path should be relative to the USD file location.

Material paths in the info:mdl:sourceAsset property must:

  1. Be present (not empty)

  2. Have the .mdl extension

  3. For relative paths, start with “./”

  4. Reference an existing MDL file

Why is it required?#

  • Broken material references

  • Non-portable assets

  • Inconsistent rendering

Examples#

# Invalid: Missing MDL path
def Material "MissingPath" (
    info:mdl:sourceAsset = @@ 
)
{
}

# Invalid: Wrong extension
def Material "WrongExtension" (
    info:mdl:sourceAsset = @abc@  # Missing .mdl extension
)
{
}

# Invalid: Relative path without ./
def Material "IncorrectRelative" (
    info:mdl:sourceAsset = @material.mdl@  # Should be ./material.mdl
)
{
}

# Invalid: Non-existent MDL file
def Material "MissingFile" (
    info:mdl:sourceAsset = @./unknown.mdl@  # File doesn't exist
)
{
}

# Valid: Proper relative path to existing MDL
def Material "ValidMaterial" (
    info:mdl:sourceAsset = @./material.mdl@
)
{
}

How to comply#

  • Ensure MDL path is specified

  • Add .mdl extension if missing

  • Prefix relative paths with “./”

  • Verify MDL file exists at specified path

For More Information#