Im writing a .map file parser and renderer and i have a question. When i take one of the planes (from each brush) in the map file and create a poly from that plane i will then chop up this poly from the other planes (in that brush). Well when i do this i need to save the back part of the split poly and discard the front. What i want to know is, how do i determine which part of the poly is the back? -SirKnight

When you use a brush plane to split your poly, you need to discard the piece that lies on the front side of the partitioning plane.

Andy.

Yes i know, thats what i said i had to do in my post. Im saying how do i tell which side of the split poly is the back?

-SirKnight

The plane normal points towards the front side. I can''t remember if the planes are defined by a cw or ccw winding, but you should be able to work it out no problem.

Andy.

Oh my god. What the hell was i thinking. I think these are the times when my brain just goes dead. I knew the normal points to the front side. Why that didnt come to me a few days ago is beyond me. Heh, when i read your post i was like, OMFG OF COURSE, and hit my self in the head. Thanks for your replys.

-SirKnight