not really a bug report but i was gathering some information about *.mtl files and found that there are several texture entries that would be interesting to be able to export.

i think these 3 would be really a great extension to have in the mtl file.

map_Ks lenna.tga # the specular texture map
map_d lenna_alpha.tga # the alpha texture map
map_bump lenna_bump.tga # the bump map

source: http://en.wikipedia.org/wiki/Wavefront_.obj_file#Material_template_library


i also spent some time creating a connection diagram, maybe somethig like that can be added to the wiki for obj export. (see attachment)