---
title: vertex
framework: scenekit
role: symbol
role_heading: Type Property
path: scenekit/scngeometrysource/semantic-swift.struct/vertex
---

# vertex

The semantic for vertex position data.

## Declaration

```swift
static let vertex: SCNGeometrySource.Semantic
```

## Discussion

Discussion For a geometry source, this semantic identifies data containing the positions of each vertex in the geometry. If you create a custom geometry using the init(sources:elements:) method, you must provide a geometry source for this semantic. For a custom shader program, you use this semantic to bind SceneKit’s vertex position data to an input attribute of the shader. Vertex position data is typically an array of three- or four-component vectors.

## See Also

### Basic Geometry Semantics

- [normal](scenekit/scngeometrysource/semantic-swift.struct/normal.md)
- [texcoord](scenekit/scngeometrysource/semantic-swift.struct/texcoord.md)