If you're only getting 'preview' on the materials list that means that the groups in the .obj don't have associated usemtl statements. One way to fix this is to edit the .obj with a text editor. After each 'g' statement in the .obj insert a usemtl statement so it looks like this: g APartName usemtl APartName Run it through the Hier converter again and you'll have an item in the materials list for each of the parts in your figure. And thanks for your kind words about the tutorials. :->