Implement an initClass() method, as described in Chapter 1, Section 1.5, “Runtime Types”. The initClass() method sets up the type identifier and file format name information for the class. This method must be called before the engine can be used in an application. Use the SO_ENGINE_INIT_CLASS() macro within the initClass() method. For example:

void
FanIn::initClass()
{
   SO_ENGINE_INIT_CLASS(FanIn, SoEngine, "Engine");
}