I use Blender to make low-poly assets for a game Im working on. In the past I’ve heard its of critical importance to triangulate your mesh before baking maps and importing into Unity. Usually I remember to do this, but recently I finished work on a rather complex element, got it set-up in Unity, scripted it, set up its state machine in Mechanim, then realized I forgot to triangulate it. I freaked for a minute before I realized my work (a complicated steam-punk gatling gun) looked fine, fantastic even compared to some of my older work. So is triangulating your mesh in your chosen modeling program really as important as I was to believe?
I would say not so much. Unity will probably triangulate your data on import, if going through a file format like FBX. I think you would have to use a custom script to import it as quads, but even then it gets triangulated before it gets rendered.
I thought the reason you were supposed to triangulate first is that it might not go how you imagine, and your animations could end up funky at the joints. If you’re getting good results, you don’t need to, but just keep it in mind as a fix for when things do go wrong.
Yup, as Wc says above, 99% of the time the only time you need to worry about triangulation is when you need to pay attention to edge folding and creases in deformable topology. Static geometry generally doesn’t care - sometimes it’s possibly to have bad edge looping on curved surfaces, which may for instance result in odd lighting or shadows… even then though, that’s a per-case hand editing task rather tha a global triangulation of your scene.
Its important that the object is comprised of triangles whilst in the editor, how that happens isn’t usually an issue, if unity does it automatically or your 3D software does it automatically it doesn’t really matter most of the time.
However for complex animations and complex objects there will be areas where you want to triangulate it manually in your 3D software (by manually making the triangles, not by clicking triangulate) so as to minimize unwanted hard edges and strange deformations.
Your triangles also make a difference to your normals, so an object evenly triangled will look perfectly fine in most lighting situations, however with rounded edges and the top of cylinders you’ll likely run into strange shading issues if the triangulation is done badly.
Normals are usually interpolated, rather than calculated, during animation to save time each frame. So, if you have a quad face that becomes nonplanar in one animated frame (most likely), the shading on those edges will definitely get messed up. But, if the model is triangulated, this situation is avoided.
Triangulation before baking is very important for a good bake.
Otherwise, as hammer mentions, non-planar ngons can end up altering the normals of their vertices after triangulation, and that means that any tangent space normal maps you’ve previously made will be invalidated.