What exactly are these? they tend to show up in the bsp's I make, but they don't seem to cause any errors. (that I know of).

They can cause visual errors,and bad radiosity casting.

Degenerate triangles usually cause open edges for me, so I end up having to fix them anyway. Not always, but most of the times they do.

A degenerate triangle is basically a triangle with no surface area. Either 2 vertices are on top of each other or you created a triangle that has 2 vertices that are the same (triangle AAB instead of ABC), both resulting in a degenerate triangle.

Open edges = fatal
Degenerate triangles = fatal/no lightmaps
Overlapping edge = fatal
Update edge = fatal
z buffered triangles = non-fatal

That picture is becoming really useful isn't it?

ha very good: wrong thread
Edited by ally on Aug 14, 2011 at 06:56 PM

There's degenerate mesh triangles and there's degenerate uv texture mapping triangles. Default xy planar uv mapping on vertical geometry like cliffs will get you degenerate texture coordinates. In the unwrap, they're just like in the lower left of Slappy's pic, above.

They cause collision to mess up and you can get phantom BSP or places where you can walk or drive through the map around the area.

Same thing, the collision will be funny, some parts won't be affected by shooting them. Not that it really matters for a weapon. Normally i ignore the errors or things smaller than a vehicle.

Normal gbxmodels can have errors. The collisions have to be sealed though. If it's a degenerate uv triangle it will probably look bad.