4 files changed, 14 insertions, 13 deletions
diff --git a/intern/cycles/render/geometry.cpp b/intern/cycles/render/geometry.cpp
index e9a70e4b3fd..60a6f598ed2 100644
--- a/intern/cycles/render/geometry.cpp
+++ b/intern/cycles/render/geometry.cpp
@@ -1917,9 +1917,12 @@ void GeometryManager::device_update(Device *device,
     }
   }
 
-  /* update the bvh even when there is no geometry so the kernel bvh data is still valid,
-   * especially when removing all of the objects during interactive renders */
-  bool need_update_scene_bvh = (scene->bvh == nullptr);
+  /* Update the BVH even when there is no geometry so the kernel's BVH data is still valid,
+   * especially when removing all of the objects during interactive renders.
+   * Also update the BVH if the transformations change, we cannot rely on tagging the Geometry
+   * as modified in this case, as we may accumulate displacement if the vertices do not also
+   * change. */
+  bool need_update_scene_bvh = (scene->bvh == nullptr || (update_flags & TRANSFORM_MODIFIED) != 0);
   {
     scoped_callback_timer timer([scene](double time) {
       if (scene->update_stats) {
diff --git a/intern/cycles/render/geometry.h b/intern/cycles/render/geometry.h
index fe30f3a807c..abdd851a089 100644
--- a/intern/cycles/render/geometry.h
+++ b/intern/cycles/render/geometry.h
@@ -189,6 +189,8 @@ class GeometryManager {
     GEOMETRY_ADDED = MESH_ADDED | HAIR_ADDED,
     GEOMETRY_REMOVED = MESH_REMOVED | HAIR_REMOVED,
 
+    TRANSFORM_MODIFIED = (1 << 10),
+
     /* tag everything in the manager for an update */
     UPDATE_ALL = ~0u,
 
diff --git a/intern/cycles/render/object.cpp b/intern/cycles/render/object.cpp
index e71d7d4a3eb..52f63685aeb 100644
--- a/intern/cycles/render/object.cpp
+++ b/intern/cycles/render/object.cpp
@@ -221,16 +221,7 @@ void Object::tag_update(Scene *scene)
 
   if (geometry) {
     if (tfm_is_modified()) {
-      /* tag the geometry as modified so the BVH is updated, but do not tag everything as modified
-       */
-      if (geometry->is_mesh() || geometry->is_volume()) {
-        Mesh *mesh = static_cast<Mesh *>(geometry);
-        mesh->tag_verts_modified();
-      }
-      else if (geometry->is_hair()) {
-        Hair *hair = static_cast<Hair *>(geometry);
-        hair->tag_curve_keys_modified();
-      }
+      flag |= ObjectManager::TRANSFORM_MODIFIED;
     }
 
     foreach (Node *node, geometry->get_used_shaders()) {
@@ -923,6 +914,10 @@ void ObjectManager::tag_update(Scene *scene, uint32_t flag)
       geometry_flag |= (GeometryManager::GEOMETRY_ADDED | GeometryManager::GEOMETRY_REMOVED);
     }
 
+    if ((flag & TRANSFORM_MODIFIED) != 0) {
+      geometry_flag |= GeometryManager::TRANSFORM_MODIFIED;
+    }
+
     scene->geometry_manager->tag_update(scene, geometry_flag);
   }
 
diff --git a/intern/cycles/render/object.h b/intern/cycles/render/object.h
index cf1b9ca510a..23682270fd1 100644
--- a/intern/cycles/render/object.h
+++ b/intern/cycles/render/object.h
@@ -133,6 +133,7 @@ class ObjectManager {
     OBJECT_REMOVED = (1 << 4),
     OBJECT_MODIFIED = (1 << 5),
     HOLDOUT_MODIFIED = (1 << 6),
+    TRANSFORM_MODIFIED = (1 << 7),
 
     /* tag everything in the manager for an update */
     UPDATE_ALL = ~0u,