void set_material(const Material *, DataFile::Collection * = 0);
const Material *get_material() const { return material.get(); }
const std::string &get_material_slot_name() const { return material_slot; }
void set_material(const Material *, DataFile::Collection * = 0);
const Material *get_material() const { return material.get(); }
const std::string &get_material_slot_name() const { return material_slot; }