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# semantic

The semantic of the vertex attribute, which describes how you want RealityKit to interpret the attribute.

```
var semantic: LowLevelMesh.VertexSemantic
```

## Discussion

RealityKit consults the vertex semantic when interpreting the data in your [`LowLevelMesh`](/documentation/RealityKit/LowLevelMesh).
For example, an attribute with the semantic value of [`LowLevelMesh.VertexSemantic.position`](/documentation/RealityKit/LowLevelMesh/VertexSemantic/position)
uses to determine the position of a vertex.

---

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