# SetRayTracingAccelerationStructure

> Sets a RayTracingAccelerationStructure to be used for Inline Ray Tracing (Ray Queries).

## Definition

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

## SetRayTracingAccelerationStructure(int, int, RayTracingAccelerationStructure)

Sets a [RayTracingAccelerationStructure](/engine/6000.3/script-reference/unityengine/rendering/raytracingaccelerationstructure.md) to be used for Inline Ray Tracing (Ray Queries).

```csharp
public void SetRayTracingAccelerationStructure(int kernelIndex, int nameID, RayTracingAccelerationStructure accelerationStructure)
```

### Parameters

**** (\[int]\(https\://learn.microsoft.com/dotnet/api/system.int32)): For which kernel the [RayTracingAccelerationStructure](/engine/6000.3/script-reference/unityengine/rendering/raytracingaccelerationstructure.md) is being set. See [ComputeShader.FindKernel](/engine/6000.3/script-reference/unityengine/computeshader/findkernel.md).**** (\[int]\(https\://learn.microsoft.com/dotnet/api/system.int32)): Property name ID, use [Shader.PropertyToID](/engine/6000.3/script-reference/unityengine/shader/propertytoid.md) to get it.**** (\[RayTracingAccelerationStructure]\(/engine/6000.3/script-reference/unityengine/rendering/raytracingaccelerationstructure)): The [RayTracingAccelerationStructure](/engine/6000.3/script-reference/unityengine/rendering/raytracingaccelerationstructure.md) object to bind.

### Remarks

Use [SystemInfo.supportsInlineRayTracing](/engine/6000.3/script-reference/unityengine/systeminfo/supportsinlineraytracing.md) to check at runtime if Inline Ray Tracing is supported by the system.

In compute shaders, ray queries can be used to perform acceleration structure traversal and geometry intersection tests. To access this functionality, the HLSL code needs to be compiled using `#pragma require inlineraytracing`.

```csharp
#include "UnityRayQuery.cginc"

#pragma require inlineraytracing
#pragma kernel CSRayQueryTest

RaytracingAccelerationStructure g_AccelStruct;
RWTexture2D<float> g_Output;

[numthreads(8,4,1)]
void CSRayQueryTest (uint3 id : SV_DispatchThreadID)
{
    const uint rayFlags = RAY_FLAG_ACCEPT_FIRST_HIT_AND_END_SEARCH;
    UnityRayQuery<rayFlags> rayQuery;

    RayDesc ray;
    ray.Origin = float3(0, 0, 0);
    ray.Direction = float3(0, 1, 0);
    ray.TMin = 0;
    ray.TMax = 10000;

    rayQuery.TraceRayInline(g_AccelStruct, rayFlags, 0xff, ray);
    rayQuery.Proceed();

    g_Output[id.xy] = (rayQuery.CommittedStatus() == COMMITTED_TRIANGLE_HIT) ? 1.0 : 0.0;
}
```

This is a simple compute shader that checks if a ray with the origin at (0, 0, 0) and direction (0, 1, 0) intersects any geometry consisting of triangles. The `g_AccelStruct` shader object can be bound using the [ComputeShader.SetRayTracingAccelerationStructure](/engine/6000.3/script-reference/unityengine/computeshader/setraytracingaccelerationstructure.md) function. The compute shader can be dispatched if [SystemInfo.supportsInlineRayTracing](/engine/6000.3/script-reference/unityengine/systeminfo/supportsinlineraytracing.md) is true.

Additional Resources: [CommandBuffer.SetGlobalRayTracingAccelerationStructure](/engine/6000.3/script-reference/unityengine/rendering/commandbuffer/setglobalraytracingaccelerationstructure.md), [SystemInfo.supportsInlineRayTracing](/engine/6000.3/script-reference/unityengine/systeminfo/supportsinlineraytracing.md).

## SetRayTracingAccelerationStructure(int, string, RayTracingAccelerationStructure)

Sets a [RayTracingAccelerationStructure](/engine/6000.3/script-reference/unityengine/rendering/raytracingaccelerationstructure.md) to be used for Inline Ray Tracing (Ray Queries).

```csharp
public void SetRayTracingAccelerationStructure(int kernelIndex, string name, RayTracingAccelerationStructure accelerationStructure)
```

### Parameters

**** (\[int]\(https\://learn.microsoft.com/dotnet/api/system.int32)): For which kernel the [RayTracingAccelerationStructure](/engine/6000.3/script-reference/unityengine/rendering/raytracingaccelerationstructure.md) is being set. See [ComputeShader.FindKernel](/engine/6000.3/script-reference/unityengine/computeshader/findkernel.md).**** (\[string]\(https\://learn.microsoft.com/dotnet/api/system.string)): Resource name in shader code.**** (\[RayTracingAccelerationStructure]\(/engine/6000.3/script-reference/unityengine/rendering/raytracingaccelerationstructure)): The [RayTracingAccelerationStructure](/engine/6000.3/script-reference/unityengine/rendering/raytracingaccelerationstructure.md) object to bind.

### Remarks

Use [SystemInfo.supportsInlineRayTracing](/engine/6000.3/script-reference/unityengine/systeminfo/supportsinlineraytracing.md) to check at runtime if Inline Ray Tracing is supported by the system.

In compute shaders, ray queries can be used to perform acceleration structure traversal and geometry intersection tests. To access this functionality, the HLSL code needs to be compiled using `#pragma require inlineraytracing`.

```csharp
#include "UnityRayQuery.cginc"

#pragma require inlineraytracing
#pragma kernel CSRayQueryTest

RaytracingAccelerationStructure g_AccelStruct;
RWTexture2D<float> g_Output;

[numthreads(8,4,1)]
void CSRayQueryTest (uint3 id : SV_DispatchThreadID)
{
    const uint rayFlags = RAY_FLAG_ACCEPT_FIRST_HIT_AND_END_SEARCH;
    UnityRayQuery<rayFlags> rayQuery;

    RayDesc ray;
    ray.Origin = float3(0, 0, 0);
    ray.Direction = float3(0, 1, 0);
    ray.TMin = 0;
    ray.TMax = 10000;

    rayQuery.TraceRayInline(g_AccelStruct, rayFlags, 0xff, ray);
    rayQuery.Proceed();

    g_Output[id.xy] = (rayQuery.CommittedStatus() == COMMITTED_TRIANGLE_HIT) ? 1.0 : 0.0;
}
```

This is a simple compute shader that checks if a ray with the origin at (0, 0, 0) and direction (0, 1, 0) intersects any geometry consisting of triangles. The `g_AccelStruct` shader object can be bound using the [ComputeShader.SetRayTracingAccelerationStructure](/engine/6000.3/script-reference/unityengine/computeshader/setraytracingaccelerationstructure.md) function. The compute shader can be dispatched if [SystemInfo.supportsInlineRayTracing](/engine/6000.3/script-reference/unityengine/systeminfo/supportsinlineraytracing.md) is true.

Additional Resources: [CommandBuffer.SetGlobalRayTracingAccelerationStructure](/engine/6000.3/script-reference/unityengine/rendering/commandbuffer/setglobalraytracingaccelerationstructure.md), [SystemInfo.supportsInlineRayTracing](/engine/6000.3/script-reference/unityengine/systeminfo/supportsinlineraytracing.md).