RotateAnimation3D start at the wrong angle about rajawali HOT 10 CLOSED

public class UIExampleRenderer extends RajawaliRenderer {
    private Plane mPlane, mChildPlane;
    private Animation3D mAnimation3D, mChildAnimation3D;
    public UIExampleRenderer(Context context) {
        super(context);
        setFrameRate(60);
    }
    
    protected void initScene() {
        mCamera.setZ(-10);
        
        SimpleMaterial planeMat = new SimpleMaterial();
        Bitmap texture = BitmapFactory.decodeResource(mContext.getResources(), R.drawable.rajawali_tex);
        planeMat.addTexture(mTextureManager.addTexture(texture));
        float h = 8*MathUtil.tan(45 / 360.0f * MathUtil.PI);
        float w = ((float)texture.getWidth()/texture.getHeight())*h;
        mPlane = new Plane(h,w,1,1);
//      mPlane.setRotZ(-90);
        mPlane.rotateAround(new Number3D(0, 0, 1), -90, true);// to show a image right.
        mPlane.setMaterial(planeMat);
        mPlane.setColor(0x55ffffff);
        addChild(mPlane);
        
        mChildPlane = new Plane(h, w, 1, 1);
        SimpleMaterial mat = new SimpleMaterial();
        mat.setUseColor(true);
        mChildPlane.setMaterial(mat);
        mChildPlane.setColor(0xff00ff00);
        mChildPlane.setX(w / 2);
        mChildPlane.setDoubleSided(true);
        mPlane.addChild(mChildPlane);
        
        mPlane.addChild(mChildPlane);
        
        Number3D axis = new Number3D(0, 0, 1);
        axis.normalize();
        
        mAnimation3D = new RotateAnimation3D(axis, 0, 360);//  the mPlane will rotZ 90 first, then start the animation.
        mAnimation3D.setDuration(2000);
        mAnimation3D.setTransformable3D(mPlane);
        
        mChildAnimation3D = new RotateAnimation3D(Axis.Y, 360);
        mChildAnimation3D.setDuration(2000);
        mChildAnimation3D.setTransformable3D(mChildPlane);
    }
    
    public void onSurfaceCreated(GL10 gl, EGLConfig config) {
        super.onSurfaceCreated(gl, config);
        
        mAnimation3D.start();
        mChildAnimation3D.start();
    }
    
    public void onDrawFrame(GL10 glUnused) {
        super.onDrawFrame(glUnused);
    }
}

BaseObject3D empty = new BaseObject3D();
Plane plane = new Plane(w,h,1,1);
plane.setX(-w);
empty.addChild(plane);

// ... now rotate the empty around its y axis