如何在Java3D中设置宇宙的功能？

如何设置使用canvas3d对象创建的SimpleUniverse实例的边界

我尝试了下面的代码，但是如果我尝试设置边界，我会得到一个“Capability not set exception”，如果我尝试设置写边界的功能，我会得到一个“Restricted access exception”

这是我的密码：

GraphicsConfiguration config = SimpleUniverse.getPreferredConfiguration();
Canvas3D canvas3d = new Canvas3D(config);
SimpleUniverse universe = new SimpleUniverse(canvas3d);
ViewingPlatform viewPlatform = universe.getViewingPlatform();

// Below line throws RestricedAccessException
viewPlatform.setCapability(ViewingPlatform.ALLOW_BOUNDS_WRITE); 
// I want to set the bounds, thus the need for the capability above
viewPlatform.setBounds(bounds);

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请帮忙

我明白了。而不是像这样建立宇宙：

GraphicsConfiguration config = SimpleUniverse.getPreferredConfiguration();
Canvas3D canvas3d = new Canvas3D(config);

SimpleUniverse universe = new SimpleUniverse(canvas3d);

我自己设置了

查看平台

，然后用它创建了宇宙：

GraphicsConfiguration config = SimpleUniverse.getPreferredConfiguration();
Canvas3D canvas3d = new Canvas3D(config);

ViewingPlatform viewingPlatform = new ViewingPlatform();
viewingPlatform.setCapability(ViewingPlatform.ALLOW_BOUNDS_WRITE);
viewingPlatform.setBounds(bounds);
Viewer viewer = new Viewer(canvas3d);    

SimpleUniverse universe = new SimpleUniverse(viewingPlatform, viewer);