# optionalShaderKeywords

> An array of Shader Keyword names used to determine the Material type.

## Definition

* **Type:** Field
* **Namespace:** [UnityEngine.Rendering](/engine/6000.5/script-reference/unityengine/rendering.md)
* **Assembly:** UnityEngine.CoreModule

```csharp
public string[] optionalShaderKeywords
```

### Remarks

Additional Resources: [RayTracingAccelerationStructure.CullInstances](/engine/6000.5/script-reference/unityengine/rendering/raytracingaccelerationstructure/cullinstances.md).