1. First I ad Diffuse material
meditmaterials[1] = Diffuse_material ()
2. I add all the textures manually from material editor
3. If I need new material with diffuse_tex I make copy of meditmaterials[1] and I can give new bitmap parameter to NewMaterial.diffuse_tex.filename
For bump, normal, diffuse I set *_input_type = 0 and *_value = 0 IF I don't need them.
Not the best way but works(kind of) for now
