Plug-ins that need to instantiate another object should do so from the super class ID and class ID via the global method CreateInstance(). The object will not appear in the scene until a node is associated with the object using the method Interface::CreateObjectNode().

INode* CreateObjectInScene(SClass_ID sid, Class_ID cid)   {
   Object* obj = static_cast<Object*>(CreateInstance(sid, cid));
   return GetCOREInterface()->CreateObjectNode(obj);
}