When navigating a scene a plug-in reference will often be retrieved without knowledge of the concrete type of the plug-in. There are two separate mechanism used for querying run-time type information from a plug-in. Each mechanism uses a method named "GetInterface()". These methods both return an abstract base class (interface) using an interface identifier.
InterfaceServer::GetInterface()
The first mechanism to retrieve interfaces is the InterfaceServer::GetInterface() which uses the type Interface_ID to identify interfaces. An Interface_ID for a given interface can usually be found as a macro in the same file as the interface definition. For example IDX8PixelShader has its interface ID defined in the same header file d3dx8.h.
The other mechanism to retrieve interfaces is Animatable::GetInterface() which uses integers to identify interface IDs. Consult the C++ Reference's "Modules > List of interface IDs supported by different plugin types" for the list of pre-defined constants used to identify interfaces. Checking whether an animatable implements a certain interface is the recommended way for determining if that animatable can be used as the type represented by that interfaced, as opposed to performing casts using dynamic_cast or static_cast.
Note: Animatable derives from InterfaceServer, so objects deriving from Animatable will need to support both InterfaceServer::GetInterface() and Animatable::GetInterface().