private void recount() {
        vertex[0].x = - w/2;
        vertex[1].x = - w/2;
        vertex[2].x = + w/2;
        vertex[3].x = + w/2;
        vertex[0].z = - v/2;
        vertex[1].z = + v/2;
        vertex[2].z = + v/2;
        vertex[3].z = - v/2;
        vertex[0].y = 0;
        vertex[1].y = 0;
        vertex[2].y = 0;
        vertex[3].y = 0;        
    }