Write a Scriptable Render Pass in URP

To create a Scriptable Render Pass in the Universal Render Pipeline (URP), follow these steps:

  1. Create a C# script that inherits the ScriptableRenderPass class. For example:

    using UnityEngine.Rendering;
using UnityEngine.Rendering.Universal;

public class ExampleRenderPass : ScriptableRenderPass
{
}

  2. In the class, add variables for the materials and textures you use in the render pass.

    For example, the following code sets up a handle to a texture, and a descriptor to configure the texture.

    private RTHandle textureHandle;
private RenderTextureDescriptor textureDescriptor;

  3. Override the Configure method to set up the render pass. Unity calls this method before executing the render pass.

    For example:

    public override void Configure(CommandBuffer cmd, RenderTextureDescriptor cameraTextureDescriptor)
{
    //Set the texture size to be the same as the camera target size.
    textureDescriptor.width = cameraTextureDescriptor.width;
    textureDescriptor.height = cameraTextureDescriptor.height;

    //Check if the descriptor has changed, and reallocate the texture handle if necessary.
    RenderingUtils.ReAllocateIfNeeded(ref textureHandle, textureDescriptor);
}

  4. Override the Execute method with your rendering commands. Unity calls this method every frame, once for each camera.

    For example:

    public override void Execute(ScriptableRenderContext context, ref RenderingData renderingData)
{
    // Get a CommandBuffer from pool
    CommandBuffer cmd = CommandBufferPool.Get();

    // Add rendering commands to the CommandBuffer
    ...

    // Execute the command buffer and release it back to the pool
    context.ExecuteCommandBuffer(cmd);
    CommandBufferPool.Release(cmd);
}

Inject a render pass into the render loop

To inject a render pass into the render loop, refer to the following:

For a complete example, refer to Example of a complete Scriptable Renderer Feature.

Additional resources