How to judge the frontest triangles?

[litstrong]

There are many triangles in the scene. I want to get triangles which i can see in the view position.

The triangle which some part of it is occluded is not the one I want to get.

Thank you!

[Dark Photon]

Don't cross-post. (Re this duplicate post) (http://www.opengl.org/discussion_boards/ubbthreads.php?ubb=showflat&Number=296003#Post2960 03)