virtual void faceCB(CBvert *, CBface *f) {
CWvec &norm = f->norm();
_form->write(norm[0]);
_form->write(" ");
_form->write(norm[1]);
_form->write(" ");
_form->write(norm[2]);
_form->write(comma);
}
virtual void faceCB(CBvert *v, CBface *) {
_form->write(str_ptr(v->index()) + comma);
}
virtual void end_faces(TriStrip *) {
_form->write(str_ptr("-1"));
if (_left) _form->write(comma);
}
virtual void begin_faces(TriStrip *str) {
_form->write(str_ptr(str->verts()[0]->index()) + comma);
_form->write(str_ptr(str->verts()[1]->index()) + comma);
_left--;
}