Run a compute shader in a render pass in URP
Analyze a render graph in URP

Create input data for a compute shader in URP

When you run a compute shader in a render pass, you can allocate a buffer to provide input data for the compute shaderA program that runs on the GPU. More info
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.

Follow these steps:

  1. Create a graphics buffer, then add a handle to it in your pass data. For example:

    // Declare an input buffer public GraphicsBuffer inputBuffer; // Add a handle to the input buffer in your pass data class PassData { ... public BufferHandle input; } // Create the buffer in the render pass constructor public ComputePass(ComputeShader computeShader) { // Create the input buffer as a structured buffer // Create the buffer with a length of 5 integers, so you can input 5 values. inputBuffer = new GraphicsBuffer(GraphicsBuffer.Target.Structured, 5, sizeof(int)); }
  2. Set the data in the buffer. For example:

    var inputValues = new List<int> { 1, 2, 3, 4, 5 }; inputBuffer.SetData(inputValues);
  3. Use the ImportBuffer render graph API to convert the buffer to a handle the render graph system can use, then set the BufferHandle field in the pass data. For example:

    BufferHandle inputHandleRG = renderGraph.ImportBuffer(inputBuffer); passData.input = inputHandleRG;
  4. Use the UseBuffer method to set the buffer as a readable buffer in the render graph system. For example:

    builder.UseBuffer(passData.input, AccessFlags.Read);
  5. In your SetRenderFunc method, use the SetComputeBufferParam API to attach the buffer to the compute shader. For example:

    // The first parameter is the compute shader // The second parameter is the function that uses the buffer // The third parameter is the RWStructuredBuffer input variable to attach the buffer to // The fourth parameter is the handle to the input buffer context.cmd.SetComputeBufferParam(passData.computeShader, passData.computeShader.FindKernel("Main"), "inputData", passData.input);

Example

For a full example, refer to the example called Compute in the Universal Render Pipeline (URP) package samples.

Additional resources


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  • Run a compute shader in a render pass in URP
    Analyze a render graph in URP