Very clear explanation. I've been using Poser for 2 years and never understood the bump map; because of your clarity, I now see that creating bump maps can solve one of my perpetual problems. I often need to make small ins and outs on the surface of something like an electronic device, to look like bezels and buttons; I was using Amorphium to make those, but that made it difficult to get "registration" between the colors and the surface shapes. Altering the coloring texture into a bump map solves that problem automatically.

My python page
My ShareCG freebies