Several of us make bump maps by hand for our 3D scene needs, and I've been one of us. But Barbara came across an applet called Shader Map Pro
, that not only auto-creates displacement maps (which are more refined and complex than bump maps), specularity maps (which can be used to mask areas that should be shiny or rough), ambient occlusion maps (good for simulating a gritty textures), and normal maps.
The thing was $20, perpetual free upgrades. Plus there's a free command line version, a nice spirit of sharing, but not awfully useful when you want a live preview. You can preview your own model with the texture you're working on, or default to a cylinder.Shader Map Pro
Not that the maps it generates can't use a little hand-tweaking in Photoshop before using them, but this is a terrific product for novices and experts alike. Normal maps are very important when you're displacing a surface—they explicitly direct the modeler what to render in which direction and can actually prevent artifacting. MapZone can generate a normal map from a preset texture and it's free, but Shader Map Pro offers flexibility to work with your own textures very quickly.
Here's a homage to Escher.