Stacking UVs and Normal Map baking!

danpV

A rather general question with a few answers I've experimented with, but what is the best way in your opinion to handle complex stacks when baking out normal maps? I notice a lot of the time, instead of just tackling the problem, unique UVs are created instead. But when it comes to creating environment models, for instance, there is a lot of overlapping to keep the resource count low.

With that prefaced, let's frame the question this way: what is best for a figure/character model, and what would work best for a generic environment piece that uses a planned texture? I'm sure there is some overlap to the technique, but I'm curious as to how this problem is tackled by this diverse pool of 3D artists!

Frump

Have as many overlapping shells as you want and just move the extras out of 0-1 (or shrink them into a corner) before baking and move them back after. It's as simple as that.

Piflik

Mostly only the 0-1 square of the UV space is used when baking. If you move your duplicates 1 square, they don't interfere with baking, but have the correct textures, when the image is tiled.

Mongrelman

I generally just export two models, one with the overlapping uvs and another with the uv islands moved off and fit somewhere else. Then load both models in, apply the same material and bake, so when it finishes I can see it on the final model too.

Ghostscape

Something else you can do with Max (and possibly other bakers?) If you have a weird stack like this:


Where the marked face is going to have a lot of wasted space under the second box, so you want to hide some stuff on top of it (the sphere unwrap in this case).

What you can do in this situation is increase the W value of the sphere, (say, to 1.0, with everything else at 0.0) and you will get a render of the box top, except where the sphere sits on top of it.

This is useful for when you have a lot of little greebly bits and a lot of intersecting mesh bits.

SideEffect

thanks Ghostscape that's a good trick. I've almost shut the W space out of existence in my head haha.