Fixed camera override in scene view

com.unity.render-pipelines.high-definition/Runtime/RenderPipeline/Camera/HDCamera.cs

@@ -455,7 +455,7 @@ internal void Update(FrameSettings currentFrameSettings, HDRenderPipeline hdrp,
                 }
                 else
                 {
-                    finalViewport = new Rect(camera.pixelRect.x, camera.pixelRect.y, camera.pixelWidth, camera.pixelHeight);
+                    finalViewport = GetPixelRect();
                 }
 
                 actualWidth = Math.Max((int)finalViewport.size.x, 1);
@@ -769,6 +769,9 @@ internal void UpdateCurrentSky(SkyManager skyManager)
                 }
             }
         }
+
+        internal void OverridePixelRect(Rect newPixelRect) => m_OverridePixelRect = newPixelRect;
+        internal void ResetPixelRect() => m_OverridePixelRect = null;
         #endregion
 
         #region Private API
@@ -800,6 +803,7 @@ public RTHandle Allocator(string id, int frameIndex, RTHandleSystem rtHandleSyst
         IEnumerator<Action<RenderTargetIdentifier, CommandBuffer>> m_RecorderCaptureActions;
         int                     m_RecorderTempRT = Shader.PropertyToID("TempRecorder");
         MaterialPropertyBlock   m_RecorderPropertyBlock = new MaterialPropertyBlock();
+        Rect?                   m_OverridePixelRect = null;
 
         void SetupCurrentMaterialQuality(CommandBuffer cmd)
         {
@@ -1234,6 +1238,14 @@ void ReleaseHistoryBuffer()
         {
             m_HistoryRTSystem.ReleaseAll();
         }
+
+        Rect GetPixelRect()
+        {
+            if (m_OverridePixelRect != null)
+                return m_OverridePixelRect.Value;
+            else
+                return camera.pixelRect;
+        }
         #endregion
     }
 }

com.unity.render-pipelines.high-definition/Runtime/RenderPipeline/HDRenderPipeline.cs

@@ -4766,6 +4766,8 @@ public struct OverrideCameraRendering : IDisposable
         {
             CommandBuffer   cmd;
             Camera          overrideCamera;
+            HDCamera        overrideHDCamera;
+            float           originalAspect;
 
             /// <summary>
             /// Overrides the current camera, changing all the matrices and view parameters for the new one.
@@ -4784,17 +4786,27 @@ public OverrideCameraRendering(CommandBuffer cmd, Camera overrideCamera)
             {
                 this.cmd = cmd;
                 this.overrideCamera = overrideCamera;
+                this.overrideHDCamera = null;
+                this.originalAspect = 0;
 
                 if (!IsContextValid(overrideCamera))
                     return;
-                
+
                 var hdrp = HDRenderPipeline.currentPipeline;
-                var hdCamera = HDCamera.GetOrCreate(overrideCamera);
+                overrideHDCamera = HDCamera.GetOrCreate(overrideCamera);
+
+                // We need to patch the pixel rect of the camera because by default the camera size is synchronized 
+                // with the game view and so it breaks in the scene view. Note that we can't use Camera.pixelRect here
+                // because when we assign it, the change is not instantaneous and is not reflected in pixelWidth/pixelHeight.
+                overrideHDCamera.OverridePixelRect(hdrp.m_CurrentHDCamera.camera.pixelRect);
+                // We also sync the aspect ratio of the camera, this time using the camera instead of HDCamera.
+                // This will update the projection matrix to match the aspect of the current rendering camera.
+                originalAspect = overrideCamera.aspect;
+                overrideCamera.aspect = (float)hdrp.m_CurrentHDCamera.camera.pixelRect.width / (float)hdrp.m_CurrentHDCamera.camera.pixelRect.height;
 
                 // Update HDCamera datas
-                hdCamera.Update(hdCamera.frameSettings, hdrp, hdrp.m_MSAASamples, hdrp.m_XRSystem.emptyPass);
-                hdCamera.UpdateAllViewConstants(false);
-                hdCamera.UpdateShaderVariablesGlobalCB(ref hdrp.m_ShaderVariablesGlobalCB, hdrp.m_FrameCount);
+                overrideHDCamera.Update(overrideHDCamera.frameSettings, hdrp, hdrp.m_MSAASamples, hdrp.m_XRSystem.emptyPass);
+                overrideHDCamera.UpdateShaderVariablesGlobalCB(ref hdrp.m_ShaderVariablesGlobalCB, hdrp.m_FrameCount);
 
                 ConstantBuffer.PushGlobal(cmd, hdrp.m_ShaderVariablesGlobalCB, HDShaderIDs._ShaderVariablesGlobal);
             }
@@ -4823,6 +4835,9 @@ void IDisposable.Dispose()
                 if (!IsContextValid(overrideCamera))
                     return;
 
+                overrideHDCamera.ResetPixelRect();
+                overrideCamera.aspect = originalAspect;
+
                 var hdrp = HDRenderPipeline.currentPipeline;
                 hdrp.m_CurrentHDCamera.UpdateShaderVariablesGlobalCB(ref hdrp.m_ShaderVariablesGlobalCB, hdrp.m_FrameCount);
                 ConstantBuffer.PushGlobal(cmd, hdrp.m_ShaderVariablesGlobalCB, HDShaderIDs._ShaderVariablesGlobal);