how to do it when is time to render objects ? disabling backface culling is one way I think , but there are other tecniques to disable rendering of hidden objects ?

"disabling backface culling is one way I think"
Backface culling is for improving the performance of your program (faces wich are facing back are not rendered).

A very good technique for removing unseen objects is frustum culling.
This is a very good tutorial in NeHe style.

sorry, I meant actually enabling it to improve performances ... I''ll check the frustum tutorial, dankje well ...

Graag gedaan!