# UpdateInstanceGeometry

> Marks the geometry of the ray tracing instance as dirty.

## Definition

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

## UpdateInstanceGeometry(Renderer)

Marks the geometry of the ray tracing instance as dirty.

```csharp
public void UpdateInstanceGeometry(Renderer renderer)
```

### Parameters

**** (\[Renderer]\(/engine/6000.5/script-reference/unityengine/renderer)): The `Renderer` associated with the ray tracing instance.

## UpdateInstanceGeometry(int)

Only ray tracing instances that use [RayTracingMode.DynamicGeometryManualUpdate](/engine/6000.5/script-reference/unityengine/experimental/rendering/raytracingmode/dynamicgeometrymanualupdate.md) can use this function to update their geometry. The function doesn't have any effects on ray tracing instances using procedural geometries (AABBs).

```csharp
public void UpdateInstanceGeometry(int handle)
```

### Parameters

**** (\[int]\(https\://learn.microsoft.com/dotnet/api/system.int32)): The handle associated with the ray tracing instance.

### Remarks

To trigger an acceleration structure build on the GPU, call [RayTracingAccelerationStructure.Build](/engine/6000.5/script-reference/unityengine/rendering/raytracingaccelerationstructure/build.md) or [CommandBuffer.BuildRayTracingAccelerationStructure](/engine/6000.5/script-reference/unityengine/rendering/commandbuffer/buildraytracingaccelerationstructure.md). After invoking one of these functions, the geometry is not considered dirty anymore.

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