Tuesday, July 03, 2007

Shave and Hair Cut - Part 2 (Uv Maps - UV Sets)

UVs are really important even though shave does a nice job of distributing hairs no matter what they may be, so if your uv's aren't equally distributed the hairs won't group in unwanted places which is great. I have found recently that it is really important to create more than one shave hair set on a surface. By selecting faces on the geometry and creating new hair this can really pack hair in places and put less hair in others.

For example the hair on a animals face is typically very fine and short. This requires one to up the hair count to fill in places that require fine fibers of hair. If you Create a UV set for the head and one for the body, you can pack more hair into the head shave node and avoid this unnecessary hair count for the body.

If you are using UV sets you can assign them to these faces which is nice. I did think this was a good option for a while but then I had to start paint too many mattes and it was difficult to keep a handle on everything. (I have found that it is best to work with one nicely laid out uv set...anything more than that is too stressful :)

Note: Try not to include uv's into a uv set that don't contain any fur (like the inside of an animals mouth). If this fur has zero density you might as well not include it so what would be essentially invisible fur is now allocated somewhere more useful.

Note (2): If you are using two uv sets I have found that sometimes it is hard to match the look of to two hair sets at it's seams. Make one of your two uv sets include both of your areas, then use the density map for each hair system to "blend" at the seam. I am still working at this technique but it seems to be a good solution for now.