---
title: MDLMaterialSemantic.userDefined
framework: modelio
role: symbol
role_heading: Case
path: modelio/mdlmaterialsemantic/userdefined
---

# MDLMaterialSemantic.userDefined

The meaning of the material property’s value is not one of the standard semantic uses recognized by Model I/O.

## Declaration

```swift
case userDefined
```

## Discussion

Discussion A renderer (or other software component processing the material) may use this material property to produce custom effects. If an asset contains more than one user-defined material property, Model I/O  gives each a unique integer value, starting with this constant’s value (0x8001).

## See Also

### Constants

- [MDLMaterialSemantic.baseColor](modelio/mdlmaterialsemantic/basecolor.md)
- [MDLMaterialSemantic.subsurface](modelio/mdlmaterialsemantic/subsurface.md)
- [MDLMaterialSemantic.metallic](modelio/mdlmaterialsemantic/metallic.md)
- [MDLMaterialSemantic.specular](modelio/mdlmaterialsemantic/specular.md)
- [MDLMaterialSemantic.specularExponent](modelio/mdlmaterialsemantic/specularexponent.md)
- [MDLMaterialSemantic.specularTint](modelio/mdlmaterialsemantic/speculartint.md)
- [MDLMaterialSemantic.roughness](modelio/mdlmaterialsemantic/roughness.md)
- [MDLMaterialSemantic.anisotropic](modelio/mdlmaterialsemantic/anisotropic.md)
- [MDLMaterialSemantic.anisotropicRotation](modelio/mdlmaterialsemantic/anisotropicrotation.md)
- [MDLMaterialSemantic.sheen](modelio/mdlmaterialsemantic/sheen.md)
- [MDLMaterialSemantic.sheenTint](modelio/mdlmaterialsemantic/sheentint.md)
- [MDLMaterialSemantic.clearcoat](modelio/mdlmaterialsemantic/clearcoat.md)
- [MDLMaterialSemantic.clearcoatGloss](modelio/mdlmaterialsemantic/clearcoatgloss.md)
- [MDLMaterialSemantic.emission](modelio/mdlmaterialsemantic/emission.md)
- [MDLMaterialSemantic.bump](modelio/mdlmaterialsemantic/bump.md)