Notations of places to examine for proper stereo VP usage

ScriptableRenderPipeline/HDRenderPipeline/HDRP/Camera/HDCamera.cs

             // _FrustumPlanes -  Also used for generating tesselation factors.  Should be fine to use the combined stereo VP
             //                   to calculate frustum planes.
 
-            // TODO: I really should be calculating my own combined view/proj in the Update code
+            // TODO: Would it be worth calculating my own combined view/proj matrix in Update?
+            // In engine, we modify the view and proj matrices accordingly in order to generate the single cull
+            // * Get the center eye view matrix, and pull it back to cover both eyes
+            // * Generated an expanded projection matrix (one method - max bound of left/right proj matrices)
+            //   and move near/far planes to match near/far locations of proj matrices located at eyes.
+            // I think using the cull matrices is valid, as long as I only use them for tess factors in shader.
+            // Using them for other calculations (like light list generation) could be problematic.
 
             var stereoCombinedViewMatrix = cullingParams.cullStereoView;
 

ScriptableRenderPipeline/HDRenderPipeline/HDRP/Lighting/LightLoop/LightLoop.cs

 
                 m_lightList.Clear();
 
-                Vector3 camPosWS = camera.transform.position;
-
                 // We need to properly reset this here otherwise if we go from 1 light to no visible light we would keep the old reference active.
                 m_CurrentSunLight = null;
                 m_CurrentSunLightShadowIndex = -1;
                         //TODO: Do not call ToArray here to avoid GC, refactor API
                         int[]   shadowRequests = m_ShadowRequests.ToArray();
                         int[]   shadowDataIndices;
+                        
+                        // Stereo: The usage of camera seems to be for the camera world space position.
+                        // For stereo, this is fine as long as this matches the head position, along with
+                        // our unified V/P/VP matrices working from that head position.
                         m_ShadowMgr.ProcessShadowRequests(m_FrameId, cullResults, camera, ShaderConfig.s_CameraRelativeRendering != 0, cullResults.visibleLights,
                             ref shadowRequestCount, shadowRequests, out shadowDataIndices);
 
                     // For now we will still apply the maximum of shadow here but we don't apply the sorting by priority + slot allocation yet
 
                     // 2. Go through all lights, convert them to GPU format.
-                    // Create simultaneously data for culling (LigthVolumeData and rendering)
+                    // Create simultaneously data for culling (LightVolumeData and rendering)
+                    Vector3 camPosWS = camera.transform.position;
+
 
                     for (int sortIndex = 0; sortIndex < sortCount; ++sortIndex)
                     {