java - Java3D 中仅在 -1.0 到 +1.0 范围内可见的对象的平移位置

Question

我有一个用 Java 编写的小程序，它应该显示 2 个球体。它工作正常，直到球体的平移超出 -1.0 到 1.0 的范围，在这种情况下，物体将会消失。我有一个 SimpleUniverse 设置，我在几个地方尝试了几个 setBounds，但我不明白它是如何消失的。真正奇怪的是，这个位置并不依赖于相机位置，因为我在靠近时的 ViewPlatform 变换上有一个 OrbitBehavior 不会显示该对象。

这是球体的设置: 公共(public)类 CelestialBody 扩展 TransformGroup {

    CelestialBody(float posX, float posY, float posZ) {
        // This is set for the dynamic behaviour.
        setCapability(TransformGroup.ALLOW_TRANSFORM_WRITE);

        Transform3D t3d = new Transform3D();
        t3d.setTranslation(new Vector3f(posX, posY, posZ));
        setTransform(t3d);
        setBounds(new BoundingSphere(new Point3d(0.0f, 0.0f, 0.0f), 10000.0f));

        Sphere sphere = new Sphere(1.0f, Sphere.GENERATE_NORMALS, 100, createAppearance());

        addChild(sphere);
    }

    private Appearance createAppearance() {
        Appearance appear = new Appearance();
        Material mat = new Material();
        mat.setShininess(100.0f);
        appear.setMaterial(mat);

        return appear;
    }
}

这是主程序:

public class CelestialApp extends Frame {

    public static void main(String[] args) {
        // TODO Auto-generated method stub
        new CelestialApp();
    }

    private SimpleUniverse universe = null;

    public CelestialApp() {
    // ...

        BranchGroup scene = constructContentBranch();
        scene.compile();

        universe = new SimpleUniverse(defaultCanvas);
        setupView();
        universe.addBranchGraph(scene);
    }

    private void setupView() {
        ViewingPlatform vp =  universe.getViewingPlatform();
        OrbitBehavior orbit = new OrbitBehavior();
        orbit.setSchedulingBounds(new BoundingSphere(new Point3d(0.0f, 0.0f, 0.0f), 10000.0f));
        vp.setNominalViewingTransform();
        vp.setViewPlatformBehavior(orbit);
    }

    private BranchGroup constructContentBranch() {
        BranchGroup scene = new BranchGroup();

        CelestialBody body1 = new CelestialBody(-2.0f, 0.0f, 0.0f);
        scene.addChild(body1);

        CelestialBody body2 = new CelestialBody(2.0f, 0.0f, -1.1f);
        scene.addChild(body2);

        PhysicalBehavior physics1 = new PhysicalBehavior(body1);
        scene.addChild(physics1);

        PhysicalBehavior physics2 = new PhysicalBehavior(body2, new Vector3d(0.0f, 0.0f, 0.0f));
        scene.addChild(physics2);

        setupLights(scene);

        return scene;
    }

    private void setupLights(BranchGroup scene) {
        AmbientLight lightA = new AmbientLight();
        lightA.setInfluencingBounds(new BoundingSphere());
        lightA.setColor(new Color3f(0.3f, 0.3f, 0.3f));
        scene.addChild(lightA);

        DirectionalLight lightD1 = new DirectionalLight();
        lightD1.setInfluencingBounds(new BoundingSphere());
        Vector3f dir = new Vector3f(-0.3f, -1.0f, -0.5f);
        dir.normalize();
        lightD1.setDirection(dir);
        lightD1.setColor(new Color3f(1.0f, 1.0f, 1.0f));
        scene.addChild(lightD1);

        Background bg = new Background(0.0f, 0.0f, 0.0f);
        bg.setApplicationBounds(new BoundingSphere());
        scene.addChild(bg);
    }
}

Answer 1

呸，没关系。光源只有一个半径为 1.0f 的边界球体，并且对象被渲染为黑色。