obj->set_material(model->find_material(name.c_str()));
if (!obj->get_material())  obj->set_material(model->find_material(name.c_str()));
static int Read_object_material_chunk	(	Model3d *model,	istream& in, 			// Header already read.	int top_len,			// Total length of this chunk.	Object3d *obj			// New object to set up.	)	{	int top_read = CHUNK_HEADER_LENGTH;	string name;			// Read material name.	top_read += Get_string(in, name);	obj->set_material(model->find_material(name.c_str()));					// Skip the rest.	in.seekg(top_len - top_read, ios::cur);	top_read = top_len;	return top_read - CHUNK_HEADER_LENGTH;	}