I've read a metric ton of stuff on the subject, but there's still a bunch of stuff I'm confused about, specifically with regards to Unreal.
I'm trying to UV my mesh, It's kinda tough with Blender as it likes to put out very crooked unwraps and I need parts of the texture to repeat with vertex for vertex precision. I'm wondering is this a good approach? I'm confused as to where UV "splits" occur. So I'm looking to any of you optimisation pros for sound advise.
1. Are more UV islands more expensive? Would a single UV island that extends beyond the limits of the texture be more efficient for repeating than multiple that are overlaid inside the UV?
2. I'm considering as an alternative to use 2 different textures/materials. Can you do two (diffuse) textures in one material? Would that be cheaper than two materials at all? Do two materials matter if the material split is along the same edge loops as a smoothing split?
3. Is using a bevel really cheaper than using smoothing splits? If the reason smoothing groups are more expensive is that doubled vertices are created, wouldn't a bevel give you the exact same final vert count?
4. Given a vert count of about 4000 (unreal count, not blender) would removing backfaces that are rarely seen make any (real) difference, or is it more important to minimize material/smoothing splits?
Exactly how is a new draw call created by an asset, smoothing? Textures? Materials? UV islands? multiple uv layouts? Sub-objects? and how expensive is that, is it more important to have less verts, or less draw calls?
EDIT: I seem to notice some unwrapped vertices don't "weld" while others do, even within the same island. Does this matter?
Thank you for your time.