Anybody know how does opencascade discrerte and display a model?

I want to display a model using opengl and opencascade. I wrote some code but when i read a iges file, it is very slow. I want the model displayed in two ways: shading and wireframe.
But i don not know how does opencascade discrete the shape and how does opencascade get shape
data? Is there anybody who knows this ?Please help me!

SunHongLei's picture

Anybody please help me .
supervisor, help me