Usage: you can reimplement this interface by deriving the supplied CATExtIVisu adapter class.
这里写得很明白,要不你得自己写所有的method
BuildRep
public virtual CATRep * BuildRep( )= 0
Builds the graphical representation of the object.
Role : It is the general method that applications have to implement to built their geometry from modeling information. The _rep data member must be valuated.
o GiveRep
public virtual CATRep * GiveRep( )
Returns the graphical representation of the object.