17. RenderGraph Compute/UAV 패턴 (SSAO/SSR류)

public override void RecordRenderGraph(RenderGraph renderGraph, ContextContainer frameData)
{
    using (var builder = renderGraph.AddComputePass<PassData>("MyComputePass", out var passData))
    {
        builder.SetRenderFunc((PassData data, ComputeGraphContext ctx) =>
        {
            // ctx.cmd로 compute 커맨드 기록
        });
    }
}

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

public sealed class ComputeAoFeature : ScriptableRendererFeature
{
    [System.Serializable]
    public sealed class Settings
    {
        public ComputeShader computeShader;
        public int kernelIndex = 0;
    }

    public Settings settings = new();

    sealed class ComputeAoPass : ScriptableRenderPass
    {
        readonly ComputeShader _cs;
        readonly int _kernel;

        class PassData
        {
            public ComputeShader cs;
            public int kernel;
            public TextureHandle depth;
            public TextureHandle normals;
            public TextureHandle aoUav;
            public Vector4 dispatch; // (gx, gy, gz, unused)
        }

        public ComputeAoPass(ComputeShader cs, int kernel)
        {
            _cs = cs;
            _kernel = kernel;
        }

        public override void RecordRenderGraph(RenderGraph renderGraph, ContextContainer frameData)
        {
            var resources = frameData.Get<UniversalResourceData>();

            // 입력(프로젝트/설정에 따라 존재 여부가 달라질 수 있음)
            TextureHandle depth = resources.activeDepthTexture;
            TextureHandle normals = resources.cameraNormalsTexture;

            // 출력 UAV 텍스처(desc는 카메라 컬러 기반으로 잡는 것을 권장)
            var aoDesc = renderGraph.GetTextureDesc(resources.activeColorTexture);
            aoDesc.name = "AO_UAV";
            aoDesc.enableRandomWrite = true;
            aoDesc.width /= 2;
            aoDesc.height /= 2;
            var ao = renderGraph.CreateTexture(aoDesc);

            using (var builder = renderGraph.AddComputePass<PassData>("Compute AO", out var passData))
            {
                passData.cs = _cs;
                passData.kernel = _kernel;
                passData.depth = depth;
                passData.normals = normals;
                passData.aoUav = ao;
                passData.dispatch = new Vector4(
                    Mathf.CeilToInt(aoDesc.width / 8.0f),
                    Mathf.CeilToInt(aoDesc.height / 8.0f),
                    1, 0);

                builder.UseTexture(passData.depth, AccessFlags.Read);
                builder.UseTexture(passData.normals, AccessFlags.Read);
                builder.UseTexture(passData.aoUav, AccessFlags.Write);

                builder.SetRenderFunc((PassData data, ComputeGraphContext ctx) =>
                {
                    var cmd = ctx.cmd;
                    cmd.SetComputeTextureParam(data.cs, data.kernel, "_CameraDepthTexture", data.depth);
                    cmd.SetComputeTextureParam(data.cs, data.kernel, "_CameraNormalsTexture", data.normals);
                    cmd.SetComputeTextureParam(data.cs, data.kernel, "_AOTexture", data.aoUav);
                    cmd.DispatchCompute(data.cs, data.kernel, (int)data.dispatch.x, (int)data.dispatch.y, (int)data.dispatch.z);
                });
            }

            // 다음 패스가 접근할 수 있도록 전역 슬롯으로 노출(선택)
            // (프로젝트 사정에 따라 필요)
            // resources.xyz = ao; 또는 cmd.SetGlobalTexture(...)
        }
    }

    ComputeAoPass _pass;

    public override void Create()
    {
        if (settings.computeShader != null)
            _pass = new ComputeAoPass(settings.computeShader, settings.kernelIndex);
    }

    public override void AddRenderPasses(ScriptableRenderer renderer, ref RenderingData renderingData)
    {
        if (_pass == null)
            return;
        renderer.EnqueuePass(_pass);
    }
}

// Compute shader snippet
RWTexture2D<float> _AOTexture;
Texture2D<float> _CameraDepthTexture;

[numthreads(8,8,1)]
void CSMain(uint3 id : SV_DispatchThreadID)
{
    float d = _CameraDepthTexture[id.xy];
    _AOTexture[id.xy] = saturate(d); // 예시: depth를 그대로 써보기
}