MistyLaraPrincess posted at 3:14PM Sun, 08 May 2016 - #4208598

does a color texture map in the bump channel make bloat?

Long time no reply... But now there's a discussion over in cgBytes linking to this thread. So...

A diffuse colour map fed into the bump channel will create overall outward displacement of the mesh, which can be described as 'bloat'. Whether this becomes obvious to the eye depends on the brightness of the colour map, the value of the bump channel input, and the shape of the base mesh itself, as BB demonstrated above. But as he said, there's no point taking risks when it's so easy to do it right.

For human skin I would say just don't use the diffuse map for bump, ever. The brightness of a decent diffuse colour map simply doesn't represent variations in skin height due to pores, veins, wrinkles, etc. - so it doesn't belong in the bump channel at all. For example, protruding veins are usually darker than the surrounding skin, but plugging this data into the bump channel would render them as depressions.

If you don't have a good, purpose-built bump map for your figure, I would suggest using procedural bump.