# ClearInstances()

> Removes all ray tracing instances from the RayTracingAccelerationStructure.

## Definition

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

```csharp
public void ClearInstances()
```

### Remarks

Note that in order to reflect this action on the GPU, building the acceleration structure has to be triggered by calling [RayTracingAccelerationStructure.Build](/engine/6000.3/script-reference/unityengine/rendering/raytracingaccelerationstructure/build.md) or [CommandBuffer.BuildRayTracingAccelerationStructure](/engine/6000.3/script-reference/unityengine/rendering/commandbuffer/buildraytracingaccelerationstructure.md).

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