Tanks for your answer, BigSerge . The thing is that i do save the object through UVmapper, and then the UV coordinates work well (UVmapper is really a great tool for working with .obj files !). But once in Carrara, i want to deform the object for a kind of "morph" animation and to do so, i have to convert the facets into a vertex object . This is what makes some of the coordinates go wrong, i guess . And i can't find out why ...