An instance of a plug-in, including primitive objects and modifiers, can be created from the super class id and class id using the Interface::CreateInstance() method or the global function CreateInstance(). The global function CreateInstance() is equivalent to calling GetCOREInterface()-> CreateInstance().
When creating an object via CreateInstance() it must be attached to a node in order to appear in the scene via the method Interface::CreateObjectNode().
For more information, Consult the C++ Reference's "Related Pages > Lists and Functions":