Is there any performance decrease to draw only using
polygons? From a programming point of view it’s a lot easier to just use polys regardless of how many points I have.
Let’s say I load a model from a file, it’s got a lot of poly’s triangle’s and quads,
If a particular face has 4 vertices is it going to make a negative impact on performance to render it as a poly?
I don’t notice any performance loss in tests I ran,
but I’m wondering if it might show up on really large models?
The problem with GL_POLYGON is, it is not an independent primitive and needs one glBegin-glEnd or one glDrawArrays or one glDrawElements, etc. call per polygon!
If your model has a lot of triangles and quads it’s MUCH faster to batch them into one primitve type GL_TRIANGLES or GL_QUADS and draw them in one single array call.
Thanks for the info,
Does it make any difference that I’m using gl lists?
In my tests I did glBegin… glEnd() for each triangle, quad or poly … which is maybe why I didn’t notice any difference.
OK, thanks for all the info!