# RemoveInstances(int, RayTracingModeMask)

> Removes ray tracing instances from the RayTracingAccelerationStructure using filtering based on layer and RayTracingMode.

## Definition

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

```csharp
public void RemoveInstances(int layerMask, RayTracingAccelerationStructure.RayTracingModeMask rayTracingModeMask)
```

### Parameters

**** (\[int]\(https\://learn.microsoft.com/dotnet/api/system.int32)): A 32-bit mask that specifies which layers to remove ray tracing instances from.**** (\[RayTracingModeMask]\(/engine/6000.5/script-reference/unityengine/rendering/raytracingaccelerationstructure/raytracingmodemask)): A mask that speficies which [RayTracingMode](/engine/6000.5/script-reference/unityengine/experimental/rendering/raytracingmode.md)s ray tracing instances must have in order to be removed.

### Remarks

Additional Resources: [RayTracingAccelerationStructure.RayTracingModeMask](/engine/6000.5/script-reference/unityengine/rendering/raytracingaccelerationstructure/raytracingmodemask.md), [RayTracingAccelerationStructure.AddInstance](/engine/6000.5/script-reference/unityengine/rendering/raytracingaccelerationstructure/addinstance.md), [RayTracingAccelerationStructure.AddInstances](/engine/6000.5/script-reference/unityengine/rendering/raytracingaccelerationstructure/addinstances.md), [RayTracingAccelerationStructure.RemoveInstance](/engine/6000.5/script-reference/unityengine/rendering/raytracingaccelerationstructure/removeinstance.md), [RayTracingAccelerationStructure.ClearInstances](/engine/6000.5/script-reference/unityengine/rendering/raytracingaccelerationstructure/clearinstances.md).

### Examples

```csharp
using UnityEngine.Rendering;
using static UnityEngine.Rendering.RayTracingAccelerationStructure;

RayTracingAccelerationStructure rtas  = new RayTracingAccelerationStructure();

// Add ray tracing instances using AddInstance, AddInstances or CullInstances methods.

// Remove all ray tracing instances using dynamic geometries that are on Layer 1 or Layer 2.
rtas.RemoveInstances((1 << 1) | (1 << 2), RayTracingModeMask.DynamicGeometry | RayTracingModeMask.DynamicGeometryManualUpdate);

// Remove all ray tracing instances.
rtas.RemoveInstances(-1, RayTracingModeMask.Everything);
```