---
title: Model I/O Constants
framework: modelio
role: collectionGroup
role_heading: API Collection
path: modelio/model-i-o-constants
---

# Model I/O Constants

## Topics

### Constants

- [MDLVertexAttributeAnisotropy](modelio/mdlvertexattributeanisotropy.md)
- [MDLVertexAttributeBinormal](modelio/mdlvertexattributebinormal.md)
- [MDLVertexAttributeBitangent](modelio/mdlvertexattributebitangent.md)
- [MDLVertexAttributeColor](modelio/mdlvertexattributecolor.md)
- [MDLVertexAttributeEdgeCrease](modelio/mdlvertexattributeedgecrease.md)
- [MDLVertexAttributeJointIndices](modelio/mdlvertexattributejointindices.md)
- [MDLVertexAttributeJointWeights](modelio/mdlvertexattributejointweights.md)
- [MDLVertexAttributeNormal](modelio/mdlvertexattributenormal.md)
- [MDLVertexAttributeOcclusionValue](modelio/mdlvertexattributeocclusionvalue.md)
- [MDLVertexAttributePosition](modelio/mdlvertexattributeposition.md)
- [MDLVertexAttributeShadingBasisU](modelio/mdlvertexattributeshadingbasisu.md)
- [MDLVertexAttributeShadingBasisV](modelio/mdlvertexattributeshadingbasisv.md)
- [MDLVertexAttributeSubdivisionStencil](modelio/mdlvertexattributesubdivisionstencil.md)
- [MDLVertexAttributeTangent](modelio/mdlvertexattributetangent.md)
- [MDLVertexAttributeTextureCoordinate](modelio/mdlvertexattributetexturecoordinate.md)
- [kUTType3dObject](modelio/kuttype3dobject.md)
- [kUTTypeAlembic](modelio/kuttypealembic.md)
- [kUTTypePolygon](modelio/kuttypepolygon.md)
- [kUTTypeStereolithography](modelio/kuttypestereolithography.md)
- [kUTTypeUniversalSceneDescription](modelio/kuttypeuniversalscenedescription.md)
- [kUTTypeUniversalSceneDescriptionMobile](modelio/kuttypeuniversalscenedescriptionmobile.md)

## See Also

### Reference

- [Model I/O Data Types](modelio/model-i-o-data-types.md)
- [Model I/O Structures](modelio/model-i-o-structures.md)
- [Model I/O Enumerations](modelio/model-i-o-enumerations.md)