android - 如何在 ARCore Sceneform 中为节点的旋转设置动画

Question

我知道 ARCore 尚不支持步行等 3D 动画，但我如何为节点的旋转设置动画？

我知道我可以设置 LocalRotation 或 WorldRotation，但如何以流畅的方式连续制作此动画？

Answer 1

最简单的方法是使用 Android Property Animation .这样做的一个例子是 Sceneform 示例“Solar System”。看看RotatingNode .这会围绕其轴旋转节点。

首先，它创建一个 ObjectAnimator它使用 LinearInterpolation 设置围绕一个圆的 4 个点之间的旋转。

private static ObjectAnimator createAnimator() {
    // Node's setLocalRotation method accepts Quaternions as parameters.
    // First, set up orientations that will animate a circle.
    Quaternion orientation1 = Quaternion.axisAngle(new Vector3(0.0f, 1.0f, 0.0f), 0);
    Quaternion orientation2 = Quaternion.axisAngle(new Vector3(0.0f, 1.0f, 0.0f), 120);
    Quaternion orientation3 = Quaternion.axisAngle(new Vector3(0.0f, 1.0f, 0.0f), 240);
    Quaternion orientation4 = Quaternion.axisAngle(new Vector3(0.0f, 1.0f, 0.0f), 360);

    ObjectAnimator orbitAnimation = new ObjectAnimator();
    orbitAnimation.setObjectValues(orientation1, orientation2, orientation3, orientation4);

    // Next, give it the localRotation property.
    orbitAnimation.setPropertyName("localRotation");

    // Use Sceneform's QuaternionEvaluator.
    orbitAnimation.setEvaluator(new QuaternionEvaluator());

    //  Allow orbitAnimation to repeat forever
    orbitAnimation.setRepeatCount(ObjectAnimator.INFINITE);
    orbitAnimation.setRepeatMode(ObjectAnimator.RESTART);
    orbitAnimation.setInterpolator(new LinearInterpolator());
    orbitAnimation.setAutoCancel(true);

    return orbitAnimation;
  }

接下来，它开始动画:

  orbitAnimation = createAnimator();
  orbitAnimation.setTarget(this);
  orbitAnimation.setDuration(getAnimationDuration());
  orbitAnimation.start();