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我想将一个可渲染的小球体放置到已经放置的模型被点击的位置，并将其锚定到该位置。这可以实现吗？如果可以，如何实现？

private void tryPlaceModel(MotionEvent motionEvent, Frame frame)
{
   if (isModelPlaced)
   {
      return;
   }

   if (motionEvent != null && frame.getCamera().getTrackingState() == TrackingState.TRACKING)
   {
    for (HitResult hit : frame.hitTest(motionEvent))
    {
    Trackable trackable = hit.getTrackable();

    if (trackable instanceof Plane && ((Plane) trackable).isPoseInPolygon(hit.getHitPose()))
    {
       // Create the Anchor.
       Anchor anchor = hit.createAnchor();
       AnchorNode anchorNode = new AnchorNode(anchor);
       anchorNode.setParent(arSceneView.getScene());

       TransformableNode model = new TransformableNode(arFragment.getTransformationSystem());
       model.setParent(anchorNode);
       model.setRenderable(andyRenderable);
       model.select();

       isModelPlaced = true;

       model.setOnTapListener((hitTestResult, motionEvent1) ->
       {
          Frame frame1 = arSceneView.getArFrame();

          if (motionEvent1 != null && frame1.getCamera().getTrackingState() == TrackingState.TRACKING)
          {
             com.google.ar.sceneform.rendering.Color color = new com.google.ar.sceneform.rendering.Color();
             color.set(Color.RED);

             MaterialFactory.makeOpaqueWithColor(this, color)
                   .thenAccept(
                         material ->
                         {
                            Pose pose = Pose.makeTranslation(hitTestResult.getPoint().x, hitTestResult.getPoint().y, hitTestResult.getPoint().z);

                            Anchor anchor1 = session.createAnchor(pose);

                            AnchorNode anchorNode1 = new AnchorNode(anchor1);
                            anchorNode1.setParent(hitTestResult.getNode());

                            Renderable sphere = ShapeFactory.makeSphere(0.05f,
                                  /* WRONG LOCATION */anchorNode1.getLocalPosition(), material);

                            Node indicatorModel = new Node();
                            indicatorModel.setParent(anchorNode1);
                            indicatorModel.setRenderable(sphere);
                         }
                   );
          }
       });
    }
 }
 }

这就是我现在的位置。该代码完全有效，除了我希望球体出现的位置。我也尝试过使用 AnchorNode.getWorldPosition，但它也是错误的。

球体出现在模型的背面。这是因为 getPoint() 方法返回射线击中平面的点（尽管字面上写它返回射线击中模型/节点的点），还是我做错了什么？

4

1 回答 1

4

Node.OnTapListener在点击事件击中一个节点时被调用，并且与平面侦听器不同，后者响应平面上的命中测试，而不是节点。

HitTestResult 具有命中的节点和在可渲染对象上命中的点的世界坐标。使用这些，您可以创建一个节点，将父节点设置为节点命中，并将世界位置设置为命中结果点：

  public void addTapHandler(Node node) {
    node.setOnTapListener((HitTestResult hitTestResult, MotionEvent motionEvent) -> {
      // Hit test point will be where the ray from the screen point intersects the model.

      // Create a sphere and attach it to the point.
      Color color = new Color(.8f, 0, 0);

      // Note: you can make one material and one sphere and reuse them.
      MaterialFactory.makeOpaqueWithColor(this, color)
              .thenAccept(material -> {
                // The sphere is in local coordinate space, so make the center 0,0,0
                Renderable sphere = ShapeFactory.makeSphere(0.05f, Vector3.zero(),
                                                            material);

                Node indicatorModel = new Node();
                indicatorModel.setParent(hitTestResult.getNode());
                indicatorModel.setWorldPosition(hitTestResult.getPoint());
                indicatorModel.setRenderable(sphere);
              });
    });
  }
于 2018-10-09T16:42:41.323 回答