This button will create a default .mtl file for the selected OBJ.

Note: This option will only be available if there is no matching .mtl file in the same directory already.

If you have an OBJ but you don't have a corresponding .mtl file, OBJ2FACT gives you the ability to create one. An OBJ can not contain any material info. But it can contain entries to identify which materials to use for different groups of polygons. These entries read "usemtl". Many applications write these usemtl entries into the OBJ. OBJ2FACT can read this "usemtl" entries and create a default .mtl file for the OBJ which can be further used to automate texture assignment.

Note: If you use this option and your OBJ does not contain any "usemtl" entries you will get an error message.

In a newly created default .mtl file all materials are generated like EIs default white plastic material together with placeholders for material related textures. If you open this file in a text editor a default material looks like this:

newmtl Head_material
Kd 1 1 1
Ks 1 1 1
d 1
Ns 0
Ka 1 1 1
Ni 1
# map_Kd diffusemap
# map_bump bumpmap
# map_Ks specularmap
# map_Ka ambientmap
# map_D transparencymap

You can edit values and texture assignment in this file. OBJ2FACT will read your edited .mtl file and write your custom materials and textures to the FACT file.

To learn how to assign textures to a model via a default OBJ2FACT .mtl file, read here.

To learn how to edit a material in a default OBJ2FACT .mtl file, read here.

To learn how to add "usemtl" entries to an OBJ file, read here.