使用rajawali框架（android）使用onTouchEvent旋转3D对象

Question

我正在创建一个Android应用程序，我将向用户显示3D模型。我用rajawali框架来显示3D模型。我想要的是用户应该能够与模型进行交互。用户可以通过向左和向右滑动来旋转3D模型。我能用两根手指实现缩放。但我无法旋转模型。这是我的Activity和Renderer的代码。

public class MainActivity extends AppCompatActivity {

private ScaleGestureDetector mScaleDetector;
private GestureDetector gestureDetector;
MyRenderer renderer;

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);

    final SurfaceView surface = new SurfaceView(this);
    surface.setFrameRate(60.0);
    surface.setRenderMode(ISurface.RENDERMODE_WHEN_DIRTY);

    // Add mSurface to your root view
    addContentView(surface, new ActionBar.LayoutParams(ViewGroup.LayoutParams.MATCH_PARENT));

    renderer = new MyRenderer(this);
    mScaleDetector = new ScaleGestureDetector(this, renderer.scaleListener);
    gestureDetector = new GestureDetector(this, renderer.gestureListener);
    surface.setSurfaceRenderer(renderer);
}

@Override
public boolean onTouchEvent(MotionEvent event) {
    mScaleDetector.onTouchEvent(event);
    if (event.getAction() == MotionEvent.ACTION_UP) {
        Log.e("MotionEvent", "up");
    } else if (event.getAction() == MotionEvent.ACTION_DOWN) {
        Log.e("MotionEvent", "down");
    }
    //Log.e("TouchEvent", event.getAction() + "");

    // Assume all touch events are consumed
    return true;
}

class MyRenderer extends Renderer implements OnFPSUpdateListener {

    Context context;
    private Sphere mEarthSphere;
    private DirectionalLight mDirectionalLight;
    public final ScaleListener scaleListener;
    public final GestureListener gestureListener;
    public boolean left, right;
    public boolean up, down;

    private final DecimalFormat mDFormat;

    public MyRenderer(Context context) {
        super(context);
        this.context = context;
        mDFormat = new DecimalFormat("#.##");

        scaleListener = new ScaleListener();
        gestureListener = new GestureListener();
        setFrameRate(60);
        setFPSUpdateListener(this);
    }

    @Override
    protected void initScene() {
        mDirectionalLight = new DirectionalLight(1f, .2f, -1.0f);
        mDirectionalLight.setColor(1.0f, 1.0f, 1.0f);
        mDirectionalLight.setPower(2);
        getCurrentScene().addLight(mDirectionalLight);

        Material material = new Material();
        material.enableLighting(true);
        material.setDiffuseMethod(new DiffuseMethod.Lambert());
        material.setColorInfluence(0);
        Texture earthTexture = new Texture("Earth", R.drawable.earthtruecolor_nasa_big);
        try {
            material.addTexture(earthTexture);

        } catch (ATexture.TextureException error) {
            Log.d("DEBUG", "TEXTURE ERROR");
        }

        mEarthSphere = new Sphere(1, 24, 24);
        mEarthSphere.setMaterial(material);
        getCurrentScene().addChild(mEarthSphere);
        getCurrentCamera().setZ(4.2f);
    }

    @Override
    public void onOffsetsChanged(float xOffset, float yOffset, float xOffsetStep, float yOffsetStep, int xPixelOffset, int yPixelOffset) {

    }

    @Override
    public void onTouchEvent(MotionEvent event) {

    }

    @Override
    protected void onRender(long ellapsedRealtime, double deltaTime) {
        super.onRender(ellapsedRealtime, deltaTime);
        mEarthSphere.rotate(Vector3.Axis.Y, 1.0);
    }


    public class ScaleListener extends
            ScaleGestureDetector.SimpleOnScaleGestureListener {
        @Override
        public boolean onScale(ScaleGestureDetector detector) {
            float scale = (float) (mEarthSphere.getScaleX() * detector
                    .getScaleFactor());
            scale = Math.max(0.1f, Math.min(scale, 5.0f));
            mEarthSphere.setScale(scale);
            return true;
        }

    }

    private class GestureListener extends GestureDetector.SimpleOnGestureListener {
        @Override
        public boolean onScroll(MotionEvent e1, MotionEvent e2, float distanceX, float distanceY) {
            //Method to rotate the 3D model

            return true;
        }
    }

    @Override
    public void onFPSUpdate(double fps) {
        System.out.println("~fps: " + mDFormat.format(fps));
    }
}

}

请告诉我如何通过手势旋转模型。