# ExtraVertexChannels

> Optional per-vertex channels that a UI Toolkit panel can opt into for use by custom shaders.

## Definition

* **Type:** Enum
* **Namespace:** [UnityEngine.UIElements](/engine/6000.6/script-reference/unityengine/uielements.md)
* **Assembly:** UnityEngine.UIElementsModule

```csharp
[Flags]
public enum ExtraVertexChannels
```

## Remarks

Each flag's value equals `1 << (int)VertexAttribute.X` for the matching semantic.

## Fields

| Value                                                                                                | Description                                                     |
| ---------------------------------------------------------------------------------------------------- | --------------------------------------------------------------- |
| [None](/engine/6000.6/script-reference/unityengine/uielements/extravertexchannels/none.md)           | No optional channels.                                           |
| [Normal](/engine/6000.6/script-reference/unityengine/uielements/extravertexchannels/normal.md)       | NORMAL (float3 in the public API; padded to float4 on the GPU). |
| [Tangent](/engine/6000.6/script-reference/unityengine/uielements/extravertexchannels/tangent.md)     | TANGENT (float4, .w = handedness).                              |
| [TexCoord1](/engine/6000.6/script-reference/unityengine/uielements/extravertexchannels/texcoord1.md) | TEXCOORD1 (float4).                                             |
| [TexCoord2](/engine/6000.6/script-reference/unityengine/uielements/extravertexchannels/texcoord2.md) | TEXCOORD2 (float4).                                             |
| [TexCoord3](/engine/6000.6/script-reference/unityengine/uielements/extravertexchannels/texcoord3.md) | TEXCOORD3 (float4).                                             |