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# LowLevelMeshResource.VertexSemantic

The intended usage of a vertex attribute.

```
enum VertexSemantic
```

## Overview

The renderer consults the vertex semantic when interpreting the data in a
`LowLevelMeshResource`. For example, an attribute with the semantic value of
[`LowLevelMeshResource.VertexSemantic.position`](/documentation/RealityKit/LowLevelMeshResource/VertexSemantic/position) determines the position of a vertex.

## Topics

### Identifying geometric attributes

[`case position`](/documentation/RealityKit/LowLevelMeshResource/VertexSemantic/position)

The semantic for vertex position data.

[`case normal`](/documentation/RealityKit/LowLevelMeshResource/VertexSemantic/normal)

The semantic for surface normal data.

[`case tangent`](/documentation/RealityKit/LowLevelMeshResource/VertexSemantic/tangent)

The semantic for surface tangent vector data.

[`case bitangent`](/documentation/RealityKit/LowLevelMeshResource/VertexSemantic/bitangent)

The semantic for surface bitangent vector data.

[`case color`](/documentation/RealityKit/LowLevelMeshResource/VertexSemantic/color)

The semantic for per-vertex color data.

### Identifying texture coordinates

[`case uv0`](/documentation/RealityKit/LowLevelMeshResource/VertexSemantic/uv0)

The semantic for the first UV channel (UV0).

[`case uv1`](/documentation/RealityKit/LowLevelMeshResource/VertexSemantic/uv1)

The semantic for the second UV channel (UV1). A shader can access this generic data.

[`case uv2`](/documentation/RealityKit/LowLevelMeshResource/VertexSemantic/uv2)

The semantic for the third UV channel (UV2). A shader can access this generic data.

[`case uv3`](/documentation/RealityKit/LowLevelMeshResource/VertexSemantic/uv3)

The semantic for the fourth UV channel (UV3). A shader can access this generic data.

[`case uv4`](/documentation/RealityKit/LowLevelMeshResource/VertexSemantic/uv4)

The semantic for the fifth UV channel (UV4). A shader can access this generic data.

[`case uv5`](/documentation/RealityKit/LowLevelMeshResource/VertexSemantic/uv5)

The semantic for the sixth UV channel (UV5). A shader can access this generic data.

[`case uv6`](/documentation/RealityKit/LowLevelMeshResource/VertexSemantic/uv6)

The semantic for the seventh UV channel (UV6). A shader can access this generic data.

[`case uv7`](/documentation/RealityKit/LowLevelMeshResource/VertexSemantic/uv7)

The semantic for the eighth UV channel (UV7). A shader can access this generic data.

### Handling unspecified semantics

[`case unspecified`](/documentation/RealityKit/LowLevelMeshResource/VertexSemantic/unspecified)

A semantic that doesn’t specify the role of the vertex.

## Relationships

### Conforms To

[`SendableMetatype`](/documentation/Swift/SendableMetatype)

[`Hashable`](/documentation/Swift/Hashable)

[`Sendable`](/documentation/Swift/Sendable)

[`Equatable`](/documentation/Swift/Equatable)

---

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