Let’s say I’ve got a retangular prism and I’d like to generate uniform normals for each face, straight outward.
If I didn’t care about normals, then I could use glDrawElements() to render it, using a vertex array of length 8 and an index array of length 24----it’s easy to re-use vertices here.
The question is, can I still re-use vertices if I want to define face normals? Since I only know how to define vertex normals, I’d think I would need to specify 3 different copies of the vertex, each with a different normal. But this seems silly; there has to be a better way to handle this (fairly common) situation. It would make no sense to totally negate the benefits of indexed vertices as soon as normals come into play.