Unity 6 URP RenderGraph 알아보기: 아키텍처와 핵심 API 정리

// 기존: renderingData.cameraData.cameraTargetDescriptor
// Unity 6:
UniversalCameraData cameraData = frameData.Get<UniversalCameraData>();
UniversalResourceData resourceData = frameData.Get<UniversalResourceData>();
UniversalRenderingData renderingData = frameData.Get<UniversalRenderingData>();
UniversalLightData lightData = frameData.Get<UniversalLightData>();

// 카메라 컬러 텍스처 간 풀스크린 블릿
Blitter.BlitCameraTexture(ctx.cmd, sourceHandle, destinationHandle, material, passIndex);

// 일반 TextureHandle 간 블릿
Blitter.BlitTexture(ctx.cmd, sourceHandle, new Vector4(1, 1, 0, 0), material, passIndex);

Shader "Hidden/CustomColorInvert"
{
    Properties
    {
        _Intensity ("Invert Intensity", Range(0.0, 1.0)) = 1.0
    }

    HLSLINCLUDE
    #include "Packages/com.unity.render-pipelines.universal/ShaderLibrary/Core.hlsl"
    #include "Packages/com.unity.render-pipelines.core/Runtime/Utilities/Blit.hlsl"

    CBUFFER_START(UnityPerMaterial)
        float _Intensity;
    CBUFFER_END

    // Pass 0: 색상 반전 (Intensity 블렌딩)
    half4 FragInvert(Varyings input) : SV_Target
    {
        UNITY_SETUP_STEREO_EYE_INDEX_POST_VERTEX(input);
        float4 color = SAMPLE_TEXTURE2D_X(_BlitTexture, sampler_LinearClamp, input.texcoord);
        half3 inverted = 1.0 - color.rgb;
        half3 finalColor = lerp(color.rgb, inverted, _Intensity);
        return half4(finalColor, color.a);
    }

    // Pass 1: 단순 복사 (Writeback)
    half4 FragCopy(Varyings input) : SV_Target
    {
        UNITY_SETUP_STEREO_EYE_INDEX_POST_VERTEX(input);
        return SAMPLE_TEXTURE2D_X(_BlitTexture, sampler_LinearClamp, input.texcoord);
    }
    ENDHLSL

    SubShader
    {
        Tags { "RenderType" = "Opaque" "RenderPipeline" = "UniversalPipeline" }
        LOD 100
        ZWrite Off
        Cull Off
        ZTest Always

        Pass
        {
            Name "ColorInvertPass"
            HLSLPROGRAM
            #pragma vertex Vert
            #pragma fragment FragInvert
            ENDHLSL
        }

        Pass
        {
            Name "CopyPass"
            HLSLPROGRAM
            #pragma vertex Vert
            #pragma fragment FragCopy
            ENDHLSL
        }
    }
}

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

public class CustomColorInvertPass : ScriptableRenderPass
{
    private Material _material;
    private float _intensity = 1.0f;

    // 1. PassData는 풀링을 위해 반드시 참조 형식(class)으로 선언
    private class PassData
    {
        public TextureHandle sourceTexture;
        public TextureHandle destinationTexture;
        public Material passMaterial;
        public float intensity;
    }

    public CustomColorInvertPass(Material mat)
    {
        _material = mat;
        renderPassEvent = RenderPassEvent.AfterRenderingPostProcessing;
    }

    public void Setup(float intensity)
    {
        _intensity = intensity;
    }

    // 2. Unity 6 RenderGraph 레코드 진입점
    public override void RecordRenderGraph(RenderGraph renderGraph, ContextContainer frameData)
    {
        UniversalResourceData resourceData = frameData.Get<UniversalResourceData>();
        UniversalCameraData cameraData = frameData.Get<UniversalCameraData>();

        if (resourceData.isActiveTargetBackBuffer)
            return;

        TextureHandle source = resourceData.activeColorTexture;

        // 3. Transient 중간 텍스처 생성
        TextureDesc desc = renderGraph.GetTextureDesc(source);
        desc.name = "Invert_Intermediate";
        desc.clearBuffer = false;
        TextureHandle intermediate = renderGraph.CreateTexture(desc);

        // 4. Pass 1: Source -> Intermediate (반전 처리 및 강도 전달)
        using (var builder = renderGraph.AddRasterRenderPass<PassData>("Invert Color Pass", out var passData))
        {
            passData.sourceTexture = source;
            passData.destinationTexture = intermediate;
            passData.passMaterial = _material;
            passData.intensity = _intensity;

            // 의존성 명시
            builder.UseTexture(source, AccessFlags.Read);
            builder.SetRenderAttachment(intermediate, 0, AccessFlags.Write);

            // 5. 실행 함수 (람다 외부 변수 캡처 금지, passData만 활용)
            builder.SetRenderFunc((PassData data, RasterGraphContext ctx) =>
            {
                data.passMaterial.SetFloat("_Intensity", data.intensity);
                Blitter.BlitTexture(ctx.cmd, data.sourceTexture, new Vector4(1, 1, 0, 0), data.passMaterial, 0);
            });
        }

        // 6. Pass 2: Intermediate -> Source (최종 복귀)
        using (var builder = renderGraph.AddRasterRenderPass<PassData>("Invert Writeback Pass", out var passData))
        {
            passData.sourceTexture = intermediate;
            passData.destinationTexture = source;
            passData.passMaterial = _material;

            builder.UseTexture(intermediate, AccessFlags.Read);
            builder.SetRenderAttachment(source, 0, AccessFlags.Write);

            builder.SetRenderFunc((PassData data, RasterGraphContext ctx) =>
            {
                Blitter.BlitTexture(ctx.cmd, data.sourceTexture, new Vector4(1, 1, 0, 0), data.passMaterial, 1);
            });
        }
    }
}

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

[Serializable]
public class CustomColorInvertFeature : ScriptableRendererFeature
{
    [SerializeField] private Shader _shader;
    [Range(0f, 1f)] [SerializeField] private float _intensity = 1.0f;
    [SerializeField] private RenderPassEvent _renderPassEvent = RenderPassEvent.AfterRenderingPostProcessing;

    private Material _material;
    private CustomColorInvertPass _customPass;

    // 1. Shader 기반 인메모리 머티리얼 생성 및 Pass 초기화
    public override void Create()
    {
        if (_shader != null)
        {
            _material = CoreUtils.CreateEngineMaterial(_shader);
        }

        _customPass = new CustomColorInvertPass(_material)
        {
            renderPassEvent = _renderPassEvent
        };
    }

    // 2. 렌더러에 Pass 큐잉 및 인스펙터 파라미터 전달
    public override void AddRenderPasses(ScriptableRenderer renderer, ref RenderingData renderingData)
    {
        if (_material == null)
            return;

        _customPass.Setup(_intensity);
        renderer.EnqueuePass(_customPass);
    }

    // 3. 런타임 머티리얼 메모리 해제
    protected override void Dispose(bool disposing)
    {
        CoreUtils.Destroy(_material);
    }
}