Fix T83915: Subdivision Surface modifier causes visual artifacts in Cycles rendered viewport - CPU and OptiX

Changing the geometry in the current scene caused the primitive offsets for all geometry to
change, but the values would not be updated in all bottom-level BVH structures. Rendering
artifacts and crashes where the result. This fixes that by ensuring all BVH structures are
updated when the primitive offsets change.

1 files changed, 2 insertions, 0 deletions

diff --git a/intern/cycles/bvh/bvh_embree.cpp b/intern/cycles/bvh/bvh_embree.cpp
index b874bda7186..c082478e5b1 100644
--- a/intern/cycles/bvh/bvh_embree.cpp
+++ b/intern/cycles/bvh/bvh_embree.cpp
@@ -682,6 +682,7 @@ void BVHEmbree::refit(Progress &progress)
         if (mesh->num_triangles() > 0) {
           RTCGeometry geom = rtcGetGeometry(scene, geom_id);
           set_tri_vertex_buffer(geom, mesh, true);
+          rtcSetGeometryUserData(geom, (void *)mesh->optix_prim_offset);
           rtcCommitGeometry(geom);
         }
       }
@@ -690,6 +691,7 @@ void BVHEmbree::refit(Progress &progress)
         if (hair->num_curves() > 0) {
           RTCGeometry geom = rtcGetGeometry(scene, geom_id + 1);
           set_curve_vertex_buffer(geom, hair, true);
+          rtcSetGeometryUserData(geom, (void *)hair->optix_prim_offset);
           rtcCommitGeometry(geom);
         }
       }