>>54804652This is kinda shitty but I think it gets the point across. Basically by putting more shadow on the border of a shadow, it gives the impression of a contour or a curve. The effect is increased by adding light to the other side. Useful for drawing metals and other shiny, hard stuff. But as you can see with the mareep picture, it works great on soft textures too.
>>54806973Give me the sauce, boss.
Please :)