Quote: "Cant You tell us exactly how You do it?"
Well I'll give some hints on my workflow...this is for photoshop so you'll have to be familiar with the program to follow this.
I'd say it's about 50/50 as far as photos and handpainting for me now. But that's a bit misleading, most of the time nowadays the pictures are so heavily altered that much of the original photo is gone...
Face textures:
I've used photo-reference for every face I've done, except for my nurse model, which was totally hand painted. If realism is the goal, I'd say using photos of actual faces is the best way to go. Unless you're going for a stylized or cartoony look of course. Line up the photos, use layer masks to blend them. Then various tools to match color and skin tones to account for bad lighting (clone stamp, etc).
Clothes:
I usually start with photos also, but now I usually just use them for realistic folds, desaturated and put into overlay or hard light mode in photoshop. From there I'll use my Wacom tablet and augment the folds with some handpainted dodge and burn. I'll also eliminate any type of heavy shadows and shading with the clone stamp tool, or lots of other methods such as the shadow/highlight tool, or the curves dialog. Generally make the lighting as even as possible. More on that later.
For other things that need totally hand painted, because I don't have good reference or it's just plain easier: First I'll do an ambient occlusion pass in 3ds max to generate a "dirt map". This gives a nice base for the texture, with shadow buildup that would occur in real life. Then I'll apply an appropriate material with an appropriate specular level, set up a few lights, and bake out a lightmap, and apply this on top of the occlusion map in photoshop, in overlay mode. Then I'll add a color layer on top of that, for the helmet in this case, yellow. At that point things are looking pretty good. I'll take my Wacom and start adding in details like scratches, anything to enhance the realism.
After the base texture is done, I'll use my secret weapon: The polyboost plugin for max which I use to clone away seams. At that point the diffuse texture is done.
The final step: I have a custom light setup in max that I use to bake out a final lightmap for the entire character. I'll apply it as the topmost layer in photoshop in normal blending mode with the opacity set to around 30-50%. Doing this helps "glue" the texture together and makes everything look more "grounded" in-game. For my future characters that have normal/specular maps then this would not be needed, as the maps will provide the shading.
I think using a combination of photos and handpainting is a good way to work. It's done like this all the time...heck Blur studios uses this approach. Unless you are working on a game that requires a specific style of art, using photos as a starting point is a time saver.
