# optionalDoubleSidedShaderKeywords

> An array of Shader Keywords for defining double-sided geometries.

## Definition

* **Type:** Field
* **Namespace:** [UnityEngine.Rendering](/engine/6000.3/script-reference/unityengine/rendering.md)
* **Assembly:** UnityEngine.CoreModule

```csharp
public string[] optionalDoubleSidedShaderKeywords
```

### Remarks

If a Shader Keyword from the list is enabled at the time when [RayTracingAccelerationStructure.CullInstances](/engine/6000.3/script-reference/unityengine/rendering/raytracingaccelerationstructure/cullinstances.md) is called, then the geometry that uses that Shader will be considered double-sided when rays encounter the geometry during acceleration structure traversal on the GPU.

Additional Resources: [RayTracingAccelerationStructure](/engine/6000.3/script-reference/unityengine/rendering/raytracingaccelerationstructure.md).