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 addNormals(withAttributeNamed:creaseThreshold:) method requires an attribute with the name MDLVertexAttributePosition.

Topics

Constants

let MDLVertexAttributeAnisotropy: String

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

let MDLVertexAttributeBinormal: String

The attribute data describes surface binormal vectors.

let MDLVertexAttributeBitangent: String

The attribute data describes surface bitangent vectors.

let MDLVertexAttributeColor: String

The attribute data describes vertex colors.

let MDLVertexAttributeEdgeCrease: String

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

let MDLVertexAttributeJointIndices: String

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

let MDLVertexAttributeJointWeights: String

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

let MDLVertexAttributeNormal: String

The attribute data describes surface normal vectors.

let MDLVertexAttributeOcclusionValue: String

The attribute data describes per-vertex ambient occlusion values.

let MDLVertexAttributePosition: String

The attribute data describes vertex positions.

let MDLVertexAttributeShadingBasisU: String

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

let MDLVertexAttributeShadingBasisV: String

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

let MDLVertexAttributeSubdivisionStencil: String

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

let MDLVertexAttributeTangent: String

The attribute data describes surface tangent vectors.

let MDLVertexAttributeTextureCoordinate: String

The attribute data describes surface normal vectors.