I''m writing a 3D Engine in OpenGl but I don''t know how to add backface culling or view testing. The problem is that I''m only 14 years old and can''t understand all that math. Does someone know a good tutorial or can someone explain it to me?

Hay Dude


Ok you are using OpenGL when polygons go down the OpenGL pipeline they will get back face culled and clipped to the view frustum, then rendered (it’s a little bit more complicated than that, but that is basically what happens). Ok I would not bother with back face culling at run time it will most probably be too costly. But it can be done at development time with a BSP algorithm. And as for “view testing” I use a method of frustum culling, there was a nice method a few months ago I don’t remember the site off hand but take a look at the old news archives at OpenGL.org.

So anyway you could take a look at OpenGL.org in the forums and do a search for BSP if you want some cool links, there was a load of links there a week or two ago.

Other forms or polygon sorting include Octree’s and Quad Trees again do a search, also the flipcode.com site is very nice, BSP, Octree’s and Quad Trees are the most common algorithms for polygon sub division, so you will find the most info on them. If you want any more info ask.


3DG

You might want to look at this