public void render() {
System.out.println("Canvas3D.render()");
GraphicsContext3D gc = GraphicsContext3D.getGC();
gc.beginTransform();
gc.setTransform(tri_trans);
gc.draw(tri_geo);
gc.endTransform();
gc.beginTransform();
gc.setTransform(quad_trans);
gc.apply(quad_app);
gc.draw(quad_geo);