I find a bug with texture path handling when opening OBJ file with textures in different directories.
1. Create model (e.g. simple sphere)
2. Create material with texture from some directory, e.g. /home/me/test/material/apple.png
3. Create group for the whole model, set texture to apple
4. Save model as OBJ to directory different than material directory, e.g. /home/me/test/model/apple.obj
5. If you look into obj file, you will see Kd is set correctly to "../material/apple.png"
6. Close mm3d and start it again
7. Open /home/me/test/model/apple.obj - the texture will dissapear because mm3d is trying to load them from "/home/me/test/apple/model/..\material\apple.png" whic is incorrect.
The bug appeared on both 1.3.8 and 1.3.6