source/blender/render/hydra/scene_delegate/blender_scene_delegate.h

@@ -21,7 +21,7 @@ namespace blender::render::hydra {
 extern struct CLG_LogRef *LOG_RENDER_HYDRA_SCENE; /* BSD - Blender Scene Delegate */
 
 class BlenderSceneDelegate : public pxr::HdSceneDelegate {
-  friend MeshData; /* has access to materials_*/
+  friend MeshData; /* has access to materials and instances */
 
  public:
   enum class EngineType { VIEWPORT = 1, FINAL, PREVIEW };

source/blender/render/hydra/scene_delegate/instancer.cc

@@ -51,9 +51,6 @@ void InstancerData::insert()
 {
   ID_LOG(2, "");
   scene_delegate_->GetRenderIndex().InsertInstancer(scene_delegate_, prim_id);
-  for (auto &it : instances_) {
-    it.second.obj_data->insert();
-  }
 }
 
 void InstancerData::remove()
@@ -149,6 +146,7 @@ void InstancerData::check_update(Object *object)
   }
   ObjectData *obj_data = it->second.obj_data.get();
   obj_data->update();
+  obj_data->transform = pxr::GfMatrix4d(1.0);
 
   pxr::HdDirtyBits bits = pxr::HdChangeTracker::Clean;
   if (object->id.recalc & ID_RECALC_TRANSFORM) {
@@ -189,6 +187,13 @@ void InstancerData::available_materials(std::set<pxr::SdfPath> &paths) const
   }
 }
 
+void InstancerData::update_as_parent()
+{
+  set_instances();
+  scene_delegate_->GetRenderIndex().GetChangeTracker().MarkInstancerDirty(
+      prim_id, pxr::HdChangeTracker::AllDirty);
+}
+
 pxr::SdfPath InstancerData::object_prim_id(Object *object) const
 {
   /* Making id of object in form like <prefix>_<pointer in 16 hex digits format> */

source/blender/render/hydra/scene_delegate/instancer.h

@@ -38,6 +38,7 @@ class InstancerData : public ObjectData {
   void check_update(Object *object);
   void check_remove(std::set<std::string> &available_objects);
   void available_materials(std::set<pxr::SdfPath> &paths) const;
+  void update_as_parent();
 
  private:
   pxr::SdfPath object_prim_id(Object *object) const;

source/blender/render/hydra/scene_delegate/mesh.cc

@@ -17,7 +17,7 @@ namespace blender::render::hydra {
 MeshData::MeshData(BlenderSceneDelegate *scene_delegate,
                    Object *object,
                    pxr::SdfPath const &prim_id)
-    : ObjectData(scene_delegate, object, prim_id)
+    : ObjectData(scene_delegate, object, prim_id), parent_(object->parent)
 {
 }
 
@@ -65,8 +65,22 @@ void MeshData::remove()
 
 void MeshData::update()
 {
-  pxr::HdDirtyBits bits = pxr::HdChangeTracker::Clean;
   Object *object = (Object *)id;
+  if (parent_ != object->parent) {
+    parent_ = object->parent;
+
+    /* Looking for corresponded instancer and update it as parent */
+    for (Object *ob = parent_; ob != nullptr; ob = ob->parent) {
+      pxr::SdfPath i_id = scene_delegate_->instancer_prim_id(ob);
+      InstancerData *i_data = scene_delegate_->instancer_data(i_id);
+      if (i_data) {
+        i_data->update_as_parent();
+        break;
+      }
+    }
+  }
+
+  pxr::HdDirtyBits bits = pxr::HdChangeTracker::Clean;
   if ((id->recalc & ID_RECALC_GEOMETRY) || (((ID *)object->data)->recalc & ID_RECALC_GEOMETRY)) {
     init();
     bits = pxr::HdChangeTracker::AllDirty;

source/blender/render/hydra/scene_delegate/mesh.h

@@ -29,7 +29,7 @@ class MeshData : public ObjectData {
   pxr::HdPrimvarDescriptorVector primvar_descriptors(pxr::HdInterpolation interpolation) const;
   pxr::SdfPath material_id() const;
 
- protected:
+ private:
   void write_mesh(Mesh *mesh);
   void write_material();
   void write_uv_maps(Mesh *mesh);
@@ -43,6 +43,7 @@ class MeshData : public ObjectData {
   pxr::VtMatrix4dArray instances_;
 
   MaterialData *mat_data_ = nullptr;
+  Object *parent_;
 };
 
 }  // namespace blender::render::hydra