Reply To: Blender – 3D Meshes – Why must they be made with (mostly) “Quads” ?

[silentheart00]

There are a few reasons (and anybody feel free to correct me if I’m wrong):

1. Quads are easy for your GPU to then break down into triangles, which makes it much easier for the GPU to compute things on it.  You have 3 points, and that makes a plane, which then you can do things like calculate shaders.  Anything above quads (called generally n-gons, more than 4 sides) is hard for your GPU to break down into triangles and do the computing it needs to do.  
2. Because of compounding problems from n-gons and even n-poles (verts with more than 4 edges joined), you’ll have a harder time later in the pipeline for things like skinning and animation.  Things will deform in wonky ways, ways that’ll take up time trying to fix than to do right in the first place.  It kind of compounds exponentially, e.g. catch something early, it’s easier to fix.  Catch something late, it’s going to take a lot of time to fix.  Really, it’s just better to do it right as early as possible.
3. I think quads are a little easier to display than triangles for humans to understand what is happening to the mesh, as well.  Sure, we could do it in triangles, but it’s easier to see how the light is falling with quads, I think.

It was never really explained to me, either, in my education, but this is kind of what I’ve gathered from working with 3D modeling and asking around.  Try creating an n-pole and try smoothing it out.  It doesn’t work so well, does it?  It just creates wonky problems later.

If anybody else has a better explanation or resources to reference, I would also like to know.  I hope this helped!