Hi guys! Which would you say is quicker to do in open gl: triangle strips, or quad strips. I''ve heard that most video cards make quads by just useing triangles any ways, if this is true would it be quicker to use triangle strips? Thanks, -J

quote:Original post by Jason2Jason
Hi guys! Which would you say is quicker to do in open gl: triangle strips, or quad strips. I''ve heard that most video cards make quads by just useing triangles any ways, if this is true would it be quicker to use triangle strips?

Thanks,

-J

This depends on which video card you have. Most current video cards are faster with triangle strips.

What do you want to do with them? If you''re trying to make quads anyway then definately use quad strips. While some cards do quad strips as triangles there are still optimizations done that make them better than manually creating quads out of traingles. Besides, on cards that do do real quads there will be an even bigger boost in performance.

If you are not trying to make quads in all cases but simply making it simple to create a quad or triangle on astrip then I don''t have an answer (It would depend on the card, which would mean targeting your optimization to a particular vender/model).

Most cards split quads as 2 triangles. So, giving triangles strip is faster than giving quad strip because it saves the split operation.

In the other hand, there are a few things that you can optimize using quad strips.
For instance, culling is theorically faster for quad strips since it is a per-polygon operation. (and in a quad strips there is 2x less polygons than in a triangle strip).
If you use auto-normal for flat shading, it is also faster to send quad strips, theorically of course.

But these are little artifacts which are insignificant for most cases, since it depends on the drivers and/or the graphics card (as every wrote before me).

Personaly, I prefer quad strips because it is very clear to display them in wireframe.