如何设置ViewingPlatform并更新TransformGroup?

时间:2009-08-19 14:45:09

标签: java opengl graphics 3d java-3d

我在TransformGroup中有一个场景,允许鼠标缩放/旋转/平移。

我需要将相机位置设置得足够远以至于我可以看到整个场景,我使用以下代码进行操作:

    // Position the position from which the user is viewing the scene
    ViewingPlatform viewPlatform = universe.getViewingPlatform();
    TransformGroup viewTransform = viewPlatform.getViewPlatformTransform();
    Transform3D t3d = new Transform3D();
    viewTransform.getTransform(t3d);
    t3d.lookAt(new Point3d(0,0,50), new Point3d(0,0,0), new Vector3d(0,1,0));
    t3d.invert();
    viewTransform.setTransform(t3d);

执行上面的代码的工作原理是我可以用鼠标操作场景。但是,如果我换掉这一行:

t3d.lookAt(new Point3d(0,0,50), new Point3d(0,0,0), new Vector3d(0,1,0));

使用:

// Change value from 50 to 90 to push the camera back further
t3d.lookAt(new Point3d(0,0,90), new Point3d(0,0,0), new Vector3d(0,1,0));

我无法用鼠标操纵屏幕。

如何在将相机向后推的同时保持使用鼠标进行变换的功能,以便我可以查看整个屏幕?

提前多多谢谢!

1 个答案:

答案 0 :(得分:4)

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

    // Manually create the viewing platform so that we can customize it
    ViewingPlatform viewingPlatform = new ViewingPlatform();

    // **** This is the part I was missing: Activation radius
    viewingPlatform.getViewPlatform().setActivationRadius(300f);

    // Set the view position back far enough so that we can see things
    TransformGroup viewTransform = viewingPlatform.getViewPlatformTransform();
    Transform3D t3d = new Transform3D();
    // Note: Now the large value works
    t3d.lookAt(new Point3d(0,0,150), new Point3d(0,0,0), new Vector3d(0,1,0));
    t3d.invert();
    viewTransform.setTransform(t3d);

    // Set back clip distance so things don't disappear 
    Viewer viewer = new Viewer(canvas3d);
    View view = viewer.getView();
    view.setBackClipDistance(300);

    SimpleUniverse universe = new SimpleUniverse(viewingPlatform, viewer);