Vertex Attributes

Names that identify semantic uses for vertex attribute data, used by the name property.

Overview

Model I/O automatically uses these names to identify vertex attribute data loaded from an asset when the asset does not already use its own custom names for vertex attributes.

Some mesh operations require that an attribute with a specific name be present in the mesh. For example, the addNormalsWithAttributeNamed:creaseThreshold: method requires an attribute with the name MDLVertexAttributePosition.

Topics

Constants

MDLVertexAttributeAnisotropy

The attribute data describes the degree to which a surface’s appearance changes in appearance when rotated about its normal vector.

MDLVertexAttributeBinormal

The attribute data describes surface binormal vectors.

MDLVertexAttributeBitangent

The attribute data describes surface bitangent vectors.

MDLVertexAttributeColor

The attribute data describes vertex colors.

MDLVertexAttributeEdgeCrease

The attribute data describes edges that should be left unmodified by surface subdivision operations.

MDLVertexAttributeJointIndices

The attribute data describes the indices of bones or joints in a skeletal animation rig.

MDLVertexAttributeJointWeights

The attribute data describes the influence factors of bones or joints on a vertex’s position for use in skeletal animation.

MDLVertexAttributeNormal

The attribute data describes surface normal vectors.

MDLVertexAttributeOcclusionValue

The attribute data describes per-vertex ambient occlusion values.

MDLVertexAttributePosition

The attribute data describes vertex positions.

MDLVertexAttributeShadingBasisU

The attribute data describes the U component of a vector basis for use in shading.

MDLVertexAttributeShadingBasisV

The attribute data describes the V component of a vector basis for use in shading.

MDLVertexAttributeSubdivisionStencil

The attribute data describes which neighboring vertices influence the effect of surface subdivision on the area around a vertex.

MDLVertexAttributeTangent

The attribute data describes surface tangent vectors.

MDLVertexAttributeTextureCoordinate

The attribute data describes surface normal vectors.