XR: Fix for Viewport Denoising Artifacts

Addresses T76003. When using VR with Eevee and viewport denoising,
scene geometry could sometimes be occluded for one eye. Solution is
to use a separate GPUViewport/GPUOffscreen for each VR view instead
of reusing a single one for rendering.

Reviewed By: Julian Eisel, Clément Foucault

Differential Revision: http://developer.blender.org/D11858

3 files changed, 9 insertions, 0 deletions

diff --git a/intern/ghost/GHOST_Types.h b/intern/ghost/GHOST_Types.h
index ff93de4f203..ddebfa7e816 100644
--- a/intern/ghost/GHOST_Types.h
+++ b/intern/ghost/GHOST_Types.h
@@ -683,6 +683,10 @@ typedef struct GHOST_XrDrawViewInfo {
 
   /** Set if the buffer should be submitted with a SRGB transfer applied. */
   char expects_srgb_buffer;
+
+  /** The view that this info represents. Not necessarily the "eye index" (e.g. for quad view
+   * systems, etc). */
+  char view_idx;
 } GHOST_XrDrawViewInfo;
 
 typedef struct GHOST_XrError {
diff --git a/intern/ghost/intern/GHOST_XrSession.cpp b/intern/ghost/intern/GHOST_XrSession.cpp
index 263b2b6cfbd..6140b2aab46 100644
--- a/intern/ghost/intern/GHOST_XrSession.cpp
+++ b/intern/ghost/intern/GHOST_XrSession.cpp
@@ -409,6 +409,7 @@ void GHOST_XrSession::drawView(GHOST_XrSwapchain &swapchain,
                                XrCompositionLayerProjectionView &r_proj_layer_view,
                                XrSpaceLocation &view_location,
                                XrView &view,
+                               uint32_t view_idx,
                                void *draw_customdata)
 {
   XrSwapchainImageBaseHeader *swapchain_image = swapchain.acquireDrawableSwapchainImage();
@@ -419,6 +420,8 @@ void GHOST_XrSession::drawView(GHOST_XrSwapchain &swapchain,
   r_proj_layer_view.fov = view.fov;
   swapchain.updateCompositionLayerProjectViewSubImage(r_proj_layer_view.subImage);
 
+  assert(view_idx < 256);
+  draw_view_info.view_idx = (char)view_idx;
   draw_view_info.expects_srgb_buffer = swapchain.isBufferSRGB();
   draw_view_info.ofsx = r_proj_layer_view.subImage.imageRect.offset.x;
   draw_view_info.ofsy = r_proj_layer_view.subImage.imageRect.offset.y;
@@ -468,6 +471,7 @@ XrCompositionLayerProjection GHOST_XrSession::drawLayer(
              r_proj_layer_views[view_idx],
              view_location,
              m_oxr->views[view_idx],
+             view_idx,
              draw_customdata);
   }
 
diff --git a/intern/ghost/intern/GHOST_XrSession.h b/intern/ghost/intern/GHOST_XrSession.h
index c871b98da46..d448585d14c 100644
--- a/intern/ghost/intern/GHOST_XrSession.h
+++ b/intern/ghost/intern/GHOST_XrSession.h
@@ -117,6 +117,7 @@ class GHOST_XrSession {
                 XrCompositionLayerProjectionView &r_proj_layer_view,
                 XrSpaceLocation &view_location,
                 XrView &view,
+                uint32_t view_idx,
                 void *draw_customdata);
   void beginFrameDrawing();
   void endFrameDrawing(std::vector<XrCompositionLayerBaseHeader *> &layers);