# instanceMask

> An instance mask which affects ray-instance masking during ray tracing on the GPU.

## Definition

* **Type:** Field
* **Namespace:** [UnityEngine.Rendering](/engine/6000.6/script-reference/unityengine/rendering.md)
* **Assembly:** UnityEngine.CoreModule

```csharp
public uint instanceMask
```

### Remarks

Typically, each ray tracing effect can use a dedicated [RayTracingInstanceCullingTest](/engine/6000.6/script-reference/unityengine/rendering/raytracinginstancecullingtest.md) configuration and different instanceMask value.

If the test passes, the instanceMask value will be ORed into a final 8-bit ray tracing instance mask. When casting rays on the GPU using *TraceRay* HLSL function, the *instanceInclusionMask* argument of *TraceRay* is ANDed with the final 8-bit instance mask to include or reject ray tracing instances during acceleration structure traversal.