Add RenderBuffers::LinkedCustomBuffers to reuse main game viewport rendered state (eg. GI) in sub-rendered view

Source/Engine/Graphics/RenderBuffers.cpp

@@ -128,6 +128,8 @@ void RenderBuffers::SetUseAlpha(bool value)
 
 const RenderBuffers::CustomBuffer* RenderBuffers::FindCustomBuffer(const StringView& name) const
 {
+    if (LinkedCustomBuffers)
+        return LinkedCustomBuffers->FindCustomBuffer(name);
     for (const CustomBuffer* e : CustomBuffers)
     {
         if (e->Name == name)
@@ -196,6 +198,7 @@ bool RenderBuffers::Init(int32 width, int32 height)
 void RenderBuffers::Release()
 {
     LastEyeAdaptationTime = 0;
+    LinkedCustomBuffers = nullptr;
 
     for (int32 i = 0; i < _resources.Count(); i++)
         _resources[i]->ReleaseGPU();

Source/Engine/Graphics/RenderBuffers.h

@@ -178,6 +178,8 @@ public:
     template<class T>
     T* GetCustomBuffer(const StringView& name)
     {
+        if (LinkedCustomBuffers)
+            return LinkedCustomBuffers->GetCustomBuffer<T>(name);
         CustomBuffer* result = (CustomBuffer*)FindCustomBuffer(name);
         if (!result)
         {
@@ -206,6 +208,11 @@ public:
     /// </remarks>
     API_FIELD(ReadOnly) GPUTexture* MotionVectors;
 
+    /// <summary>
+    /// External Render Buffers used to redirect FindCustomBuffer/GetCustomBuffer calls. Can be linked to other rendering task (eg. main game viewport) to reuse graphics effect state from it (eg. use GI from main game view in in-game camera renderer).
+    /// </summary>
+    API_FIELD() RenderBuffers* LinkedCustomBuffers = nullptr;
+
 public:
     /// <summary>
     /// Allocates the buffers.

Source/Engine/Renderer/Config.h

@@ -117,6 +117,3 @@ PACK_STRUCT(struct ProbeData {
 
 // Default format for the shadow map textures
 #define SHADOW_MAPS_FORMAT PixelFormat::D16_UNorm
-
-// Material distortion offsets output pass (material uses PS_Distortion, ForwardPass resolves the offsets)
-#define Distortion_Pass_Output_Format PixelFormat::R8G8B8A8_UNorm

Source/Engine/Renderer/ForwardPass.cpp

@@ -107,7 +107,7 @@ void ForwardPass::Render(RenderContext& renderContext, GPUTexture* input, GPUTex
         const int32 height = renderContext.Buffers->GetHeight();
         const int32 distortionWidth = width;
         const int32 distortionHeight = height;
-        const auto tempDesc = GPUTextureDescription::New2D(distortionWidth, distortionHeight, Distortion_Pass_Output_Format);
+        const auto tempDesc = GPUTextureDescription::New2D(distortionWidth, distortionHeight, PixelFormat::R8G8B8A8_UNorm);
         auto distortionRT = RenderTargetPool::Get(tempDesc);
         RENDER_TARGET_POOL_SET_NAME(distortionRT, "Forward.Distortion");
 
@@ -119,15 +119,13 @@ void ForwardPass::Render(RenderContext& renderContext, GPUTexture* input, GPUTex
         // Render distortion pass
         view.Pass = DrawPass::Distortion;
         mainCache->ExecuteDrawCalls(renderContext, distortionList);
+
+        // Copy combined frame with distortion from transparent materials
         context->SetViewportAndScissors((float)width, (float)height);
         context->ResetRenderTarget();
         context->ResetSR();
-
-        // Bind inputs
         context->BindSR(0, input);
         context->BindSR(1, distortionRT);
-
-        // Copy combined frame with distortion from transparent materials
         context->SetRenderTarget(output->View());
         context->SetState(_psApplyDistortion);
         context->DrawFullscreenTriangle();

Source/Engine/Renderer/RenderList.cpp

@@ -2,9 +2,6 @@
 
 #include "RenderList.h"
 #include "Engine/Core/Collections/Sorting.h"
-#if !BUILD_RELEASE
-#include "Engine/Core/Utilities.h"
-#endif
 #include "Engine/Graphics/Materials/IMaterial.h"
 #include "Engine/Graphics/RenderTask.h"
 #include "Engine/Graphics/GPUContext.h"
@@ -649,9 +646,6 @@ void RenderList::ExecuteDrawCalls(const RenderContext& renderContext, DrawCallsL
 {
     if (list.IsEmpty())
         return;
-#if !BUILD_RELEASE
-    CHECK(Utilities::CountBits((uint32)renderContext.View.Pass) == 1); // Ensure proper pass is set (single bit flag)
-#endif
     PROFILE_GPU_CPU("Drawing");
     const auto* drawCallsData = drawCalls.Get();
     const auto* listData = list.Indices.Get();

Source/Shaders/GI/DDGI.shader

@@ -576,7 +576,7 @@ void PS_IndirectLighting(Quad_VS2PS input, out float4 output : SV_Target0)
     // Calculate lighting
     float3 diffuseColor = GetDiffuseColor(gBuffer);
     float3 diffuse = Diffuse_Lambert(diffuseColor);
-    output = float4(diffuse * irradiance * gBuffer.AO, saturate(length(irradiance)));
+    output.rgb = diffuse * irradiance * gBuffer.AO;
 }
 
 #endif