I got Maya working again! So here's the tut I promised. (tagging
Quanyails)
Unwrapping Statagem in Maya
This workflow was something I developed over time, so it works for me but some artists may prefer different ways. To find what works for you just keep practicing! Anyway, first delete all the duplicate pieces of Stratagem's mesh. Once unwapping is done they can be mirrored again to save us time. Leave the ones in the middle alone (don't chop them in half).
Select all objects and create a planar map (Create UVs > Planar Mapping). It doesn't matter what axis you use.
Go to edge mode (F9) and select the edges where you want seams to appear. UV mapping is about finding a "sweet spot" between the number of seams and the continuity of UVs. You don't want too many seams because they're ugly, but too few isn't good either because your texture ends up looking distorted. Luckily, Stratagem's pieces are all sphere-like so the idea is simple; the sweet spot to unwrapping a sphere is have the seam line going along half its circumference. The best place to put it is along the back, because we want the front of the character to look best. So I selected the back edges of each shape:
In the UV Texture editor, go to Polygons > Cut UV Edges. The selected edges are now seams.
Go to UV mode (F12), select all UVs on the map, then go to Tool > Smooth UV Tool. Drag the "unfold" label towards the right and watch the magic happen! Unfortunately it only does one shell at a time, so you have to go through them one by one.
Some shells won't unfold properly, for two possible reasons:
- A) there's not enough seams, or
- B) the UVs are too tangled up.
To decide if the problem is A or B, think of untangling a rope - if the edges are too glued together that it's physically impossible to untangle them, then it's problem A. If you think it's possible to untangle them (just that Maya wasn't able to), then it's problem B. To fix A, select more edges and go to Polygons > Cut UV Edges. To fix B, go to Tool > UV Smudge Tool and mess up the UVs a bit. All it does is give the smooth tool a new arrangement to work from, which will then hopefully work. If not - keep smudging and unfolding, and eventually it'll work (if still not then perhaps it's problem A and you need to cut more edges!)
Now that everything's unfolded, it's time to mirror the objects we deleted before. Select the originals, duplicate (Edit > Duplicate), group (Edit > Group), set scaleX to -1, then ungroup (Edit > Ungroup).
The last step is organizing the UV map. Move, rotate or scale the shells until you get something tidy. For Stratagem I'd group the shells by their color (grey, brown or pink) to make things easier for the texture artist.
To test our UVs, I made a texture from a grey canvas with a pink square and brown rectangle, and overlayed it with fractal clouds.
Here's a quick render:
Wow that looks silly, but it's done in 15 minutes so uh, cut me some slack. :P
In a nutshell:
- create planar map
- mark edges to seam
- unfold UVs
- layout UV map