newmtl default
Ka 0 0 0
Kd 0 0 0
Ks 0 0 0
Kt 0.1 0.2 0.3
map_Ka -clamp on ambient.jpg
map_Kd -o 0.1 diffuse.jpg
map_Ks -s 0.1 0.2 specular.jpg
map_Ns -t 0.1 0.2 0.3 specular_highlight.jpg
map_bump -bm 3 bumpmap.jpg

newmtl bm2
Ka 0 0 0
Kd 0 0 0
Ks 0 0 0
Kt 0.1 0.2 0.3
# blendu
map_Kd -blendu on diffuse.jpg
map_Ks -blendv off specular.jpg
map_Ns -mm 0.1 0.3 specular_highlight.jpg
# -bm after filename
map_bump -imfchan r bumpmap2.jpg -bm 1.5

newmtl bm3
Ka 0 0 0
Kd 0 0 0
Ks 0 0 0
Kt 0.1 0.2 0.3
# type
map_Kd -type sphere diffuse.jpg
map_Ks -type cube_top specular.jpg
map_Ns -type cube_bottom specular_highlight.jpg
map_Ka -type cube_left ambient.jpg
map_d -type cube_right alpha.jpg
map_bump -type cube_front bump.jpg
disp -type cube_back displacement.jpg