Fix constant lighting change in VR view when rotating head

We have to explicitly enable fixed world space lighting. This was in
fact already done, but overridden by the code to sync the 3D View
shading settings to the VR view.

2 files changed, 10 insertions, 2 deletions

diff --git a/source/blender/blenloader/intern/versioning_280.c b/source/blender/blenloader/intern/versioning_280.c
index 111ac728cc3..51df61143e0 100644
--- a/source/blender/blenloader/intern/versioning_280.c
+++ b/source/blender/blenloader/intern/versioning_280.c
@@ -4951,8 +4951,6 @@ void blo_do_versions_280(FileData *fd, Library *UNUSED(lib), Main *bmain)
         const View3D *v3d_default = DNA_struct_default_get(View3D);
 
         wm->xr.session_settings.shading = v3d_default->shading;
-        /* Don't rotate light with the viewer by default, make it fixed. */
-        wm->xr.session_settings.shading.flag |= V3D_SHADING_WORLD_ORIENTATION;
         wm->xr.session_settings.draw_flags = (V3D_OFSDRAW_SHOW_GRIDFLOOR |
                                               V3D_OFSDRAW_SHOW_ANNOTATION);
         wm->xr.session_settings.clip_start = v3d_default->clip_start;
@@ -5110,6 +5108,12 @@ void blo_do_versions_280(FileData *fd, Library *UNUSED(lib), Main *bmain)
       }
     }
 
+    for (wmWindowManager *wm = bmain->wm.first; wm; wm = wm->id.next) {
+      /* Don't rotate light with the viewer by default, make it fixed. Shading settings can't be
+       * edited and this flag should always be set. So we can always execute this. */
+      wm->xr.session_settings.shading.flag |= V3D_SHADING_WORLD_ORIENTATION;
+    }
+
     /* Keep this block, even when empty. */
   }
 }
diff --git a/source/blender/editors/space_view3d/view3d_view.c b/source/blender/editors/space_view3d/view3d_view.c
index 66efa5b5de3..839f8c60a66 100644
--- a/source/blender/editors/space_view3d/view3d_view.c
+++ b/source/blender/editors/space_view3d/view3d_view.c
@@ -1733,6 +1733,8 @@ void ED_view3d_xr_shading_update(wmWindowManager *wm, const View3D *v3d, const S
 {
   if (v3d->runtime.flag & V3D_RUNTIME_XR_SESSION_ROOT) {
     View3DShading *xr_shading = &wm->xr.session_settings.shading;
+    /* Flags that shouldn't be overridden by the 3D View shading. */
+    const int flag_copy = V3D_SHADING_WORLD_ORIENTATION;
 
     BLI_assert(WM_xr_session_exists(&wm->xr));
 
@@ -1750,7 +1752,9 @@ void ED_view3d_xr_shading_update(wmWindowManager *wm, const View3D *v3d, const S
     }
 
     /* Copy shading from View3D to VR view. */
+    const int old_xr_shading_flag = xr_shading->flag;
     *xr_shading = v3d->shading;
+    xr_shading->flag = (xr_shading->flag & ~flag_copy) | (old_xr_shading_flag & flag_copy);
     if (v3d->shading.prop) {
       xr_shading->prop = IDP_CopyProperty(xr_shading->prop);
     }