Attached Link: http://www.bryceworks.com/current_bryce/dead_end_pc.html

Bump mapping is just a render effect, does nothing to the actual geometry. What you're really looking for is a 3D app that does displacement mapping from an image that can be converted to a fixed mesh for export to something like .OBJ. I have that feature with the Form*z modeler but I'm not sure what other 3D apps offer this. The link is to a Bryce image of mine that used this technique for the brick walls and "cracked" concrete alley floor.