Added utility custom pass to copy current depth buffer to custom depth

Assets/CustomPasses/CurrentDepthToCustomDepth/CurrentDepthToCustomDepth.cs

@@ -0,0 +1,41 @@
+using UnityEditor.Rendering.HighDefinition;
+using UnityEngine;
+using UnityEngine.Rendering.HighDefinition;
+using UnityEngine.Rendering;
+
+#if UNITY_EDITOR
+[CustomPassDrawer(typeof(CurrentDepthToCustomDepth))]
+class CurrentDepthToCustomDepthDrawer : CustomPassDrawer
+{
+    protected override PassUIFlag commonPassUIFlags => PassUIFlag.Name;
+}
+#endif
+
+class CurrentDepthToCustomDepth : CustomPass
+{
+    Material depthToCustomDepth;
+
+    [SerializeField, HideInInspector]
+    Shader depthToCustomDepthShader;
+
+    readonly int currentCameraDepth = Shader.PropertyToID("_CurrentCameraDepth");
+
+    protected override void Setup(ScriptableRenderContext renderContext, CommandBuffer cmd)
+    {
+        if (depthToCustomDepthShader == null)
+            depthToCustomDepthShader = Shader.Find("Hidden/FullScreen/CurrentDepthToCustomDepth");
+        depthToCustomDepth = CoreUtils.CreateEngineMaterial(depthToCustomDepthShader);
+    }
+
+    protected override void Execute(CustomPassContext ctx)
+    {
+        depthToCustomDepth.SetTexture(currentCameraDepth, ctx.cameraDepthBuffer);
+        CoreUtils.SetRenderTarget(ctx.cmd, ctx.customDepthBuffer.Value);
+        CoreUtils.DrawFullScreen(ctx.cmd, depthToCustomDepth, shaderPassId: 0);
+    }
+
+    protected override void Cleanup()
+    {
+        CoreUtils.Destroy(depthToCustomDepth);
+    }
+}

Assets/CustomPasses/CurrentDepthToCustomDepth/CurrentDepthToCustomDepth.shader

@@ -0,0 +1,64 @@
+Shader "Hidden/FullScreen/CurrentDepthToCustomDepth"
+{
+    HLSLINCLUDE
+
+    #pragma vertex Vert
+
+    #pragma target 4.5
+    #pragma only_renderers d3d11 playstation xboxone xboxseries vulkan metal switch
+
+    #include "Packages/com.unity.render-pipelines.high-definition/Runtime/RenderPipeline/RenderPass/CustomPass/CustomPassCommon.hlsl"
+    #pragma enable_d3d11_debug_symbols
+
+    // The PositionInputs struct allow you to retrieve a lot of useful information for your fullScreenShader:
+    // struct PositionInputs
+    // {
+    //     float3 positionWS;  // World space position (could be camera-relative)
+    //     float2 positionNDC; // Normalized screen coordinates within the viewport    : [0, 1) (with the half-pixel offset)
+    //     uint2  positionSS;  // Screen space pixel coordinates                       : [0, NumPixels)
+    //     uint2  tileCoord;   // Screen tile coordinates                              : [0, NumTiles)
+    //     float  deviceDepth; // Depth from the depth buffer                          : [0, 1] (typically reversed)
+    //     float  linearDepth; // View space Z coordinate                              : [Near, Far]
+    // };
+
+    // To sample custom buffers, you have access to these functions:
+    // But be careful, on most platforms you can't sample to the bound color buffer. It means that you
+    // can't use the SampleCustomColor when the pass color buffer is set to custom (and same for camera the buffer).
+    // float4 CustomPassSampleCustomColor(float2 uv);
+    // float4 CustomPassLoadCustomColor(uint2 pixelCoords);
+    // float LoadCustomDepth(uint2 pixelCoords);
+    // float SampleCustomDepth(float2 uv);
+
+    // There are also a lot of utility function you can use inside Common.hlsl and Color.hlsl,
+    // you can check them out in the source code of the core SRP package.
+
+    TEXTURE2D_X(_CurrentCameraDepth);
+
+    float FullScreenPass(Varyings varyings) : SV_Depth
+    {
+        UNITY_SETUP_STEREO_EYE_INDEX_POST_VERTEX(varyings);
+
+        return LOAD_TEXTURE2D_X(_CurrentCameraDepth, uint2(varyings.positionCS.xy));
+    }
+
+    ENDHLSL
+
+    SubShader
+    {
+        Tags{ "RenderPipeline" = "HDRenderPipeline" }
+        Pass
+        {
+            Name "Custom Pass 0"
+
+            ZWrite On
+            ZTest Always
+            Blend Off
+            Cull Off
+
+            HLSLPROGRAM
+                #pragma fragment FullScreenPass
+            ENDHLSL
+        }
+    }
+    Fallback Off
+}

README.md

@@ -157,3 +157,9 @@ Sources: [Assets/CustomPasses/Wetness](https://github.com/alelievr/HDRP-Custom-P
 It's also compatible with ShaderGraph using the SubGraph "EncodeIntoToNormalBuffer".
 
 https://user-images.githubusercontent.com/6877923/195407733-1e73b63c-5ba6-488f-829d-d4cb0d0b1412.mp4
+
+## Current Depth To Custom Depth
+
+Duing HDRP rendering, you only have access to the depth buffer that contains all opaque objects, the depth texture is not updated when rendering transparent with depth pre/post passes.
+
+This custom pass copies the current camera depth (up to date with the current injection point) to the custom depth buffer. The custom depth buffer can then be sampled in a fullscreen shader graph using the custom depth node.