I've an another problem all the materials are white :/
if somebody get the same problem and have a solution can he explain to me an some other people get the same problem pls ^^
thanks you in advance ^^
It may be a problem with Cinema 4D
OBJ file has different problems with different software.
Check import settings in Cinema.... Make sure you have exported textures (a texture folder will be created) and also make sure that *.obj and *.mtl files are right next to that folder.
One thing you can try is to copy *.obj and *.mtl file into "texture" folder you have exported. That way Cinema will find surely find all *.png files. If that does not help, try to import it in different program (for example Blender, it is free) and then export it in another format, more stable and more supported with Cinema 4D
I hope that helps. If not, let me know.