如何在JMonkeyEngine中启用抗锯齿？

import com.jme3.app.SimpleApplication;
import com.jme3.renderer.ViewPort;
import com.jme3.renderer.queue.RenderQueue;
import com.jme3.renderer.queue.RenderQueue.ShadowMode;
import com.jme3.scene.Node;

public class AntiAliasingExample extends SimpleApplication {

    public static void main(String[] args) {
        AntiAliasingExample app = new AntiAliasingExample();
        app.start();
    }

    @Override
    public void simpleInitApp() {
        // 创建一个节点并添加到场景图中
        Node rootNode = new Node("RootNode");
        rootNode.attachChild(new com.jme3.scene.shape.Box(1, 1, 1));
        rootNode.setShadowMode(ShadowMode.Off);

        // 获取当前的ViewPort
        ViewPort viewPort = renderManager.getCurrentViewport();

        // 启用抗锯齿
        viewPort.setClearFlags(true, true, true);
        viewPort.setBackgroundColor(ColorRGBA.Black);
        viewPort.setAntialias(true);

        // 设置渲染队列
        viewPort.setRenderQueue(renderQueue);
    }
}