3D clipping & gluPerspective()
i am a little confused about 3D clipping using gluPerspective(). from what ive read, i thought that anything out side of the viewable 'perspective' should not be rendered (ie. no projection calculations done). but i did a little test and i dont think this is the case...
i added 50 high poly models to an area of the scene. when looking at them (they are inside viewable frustum) the program was slow and choppy as excpected. When i turned the camera away from them (no longer in the viewable perspective/frustum) the program was still slow and choppy which implies rendering calculations are still being done for these non-viewable objects.
my question is: do i have to manually calculate what is viewable and only draw/render that? or can openGL (gluPerspective) do this for me. if it can do the 3D clipping for me, what am i doing wrong??
this is how i set up my perspective...