如何将对象从锚点移动到锚点？
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【中文标题】如何将对象从锚点移动到锚点？【英文标题】：How to move object from Anchor to Anchor? 【发布时间】：2018-12-22 13:34:38 【问题描述】：我的用例是：
-
点击屏幕并将“点”保存为起始锚点
第二次点击屏幕并将“点”保存为结束锚点
按下按钮，将对象从起点移动到终点锚点
我已经构建了自己的节点，该节点使用ObjectAnimator，类似于太阳系示例。我唯一的问题是我不知道如何确定评估者的起点和终点。我的第一个想法是从开始和结束锚点的 Pose 中获取 x,y,z
Vector3 start = new Vector3(startAnchor.getPose().tx(), startAnchor.getPose().ty(), startAnchor.getPose().tz());
Vector3 end = new Vector3(endAnchor.getPose().tx(), endAnchor.getPose().ty(), endAnchor.getPose().tz());
…
movingAnimation.setObjectValues(startingPoint, endPoint);
movingAnimation.setPropertyName("localPosition");
movingAnimation.setEvaluator(new Vector3Evaluator());
但是当我这样做时，动画是从完全不同的地方完成的。
我没有找到任何有关此类操作的内置工具的参考。 我正在使用 Sceneform。
那么问题来了：如何制作一个流畅的动画（一张简单的幻灯片就够了）从锚点A到锚点B？
【问题讨论】：
【参考方案1】：我在 HelloSceneform 示例中执行了此操作。我创建了第一个 AnchorNode 并将“andy”节点添加为子节点。在下一次点击时，我创建了 endPosition AnchorNode 并开始动画以移动到该位置。
要记住的是，如果您使用具有不同父级的对象的位置，您希望使用 worldPosition 与 localPosition。
private void onPlaneTap(HitResult hitResult, Plane plane, MotionEvent motionEvent)
if (andyRenderable == null)
return;
// Create the Anchor.
Anchor anchor = hitResult.createAnchor();
// Create the starting position.
if (startNode == null)
startNode = new AnchorNode(anchor);
startNode.setParent(arFragment.getArSceneView().getScene());
// Create the transformable andy and add it to the anchor.
andy = new Node();
andy.setParent(startNode);
andy.setRenderable(andyRenderable);
else
// Create the end position and start the animation.
endNode = new AnchorNode(anchor);
endNode.setParent(arFragment.getArSceneView().getScene());
startWalking();
private void startWalking()
objectAnimation = new ObjectAnimator();
objectAnimation.setAutoCancel(true);
objectAnimation.setTarget(andy);
// All the positions should be world positions
// The first position is the start, and the second is the end.
objectAnimation.setObjectValues(andy.getWorldPosition(), endNode.getWorldPosition());
// Use setWorldPosition to position andy.
objectAnimation.setPropertyName("worldPosition");
// The Vector3Evaluator is used to evaluator 2 vector3 and return the next
// vector3. The default is to use lerp.
objectAnimation.setEvaluator(new Vector3Evaluator());
// This makes the animation linear (smooth and uniform).
objectAnimation.setInterpolator(new LinearInterpolator());
// Duration in ms of the animation.
objectAnimation.setDuration(500);
objectAnimation.start();
【讨论】：
【参考方案2】：/**
* This is an example activity that uses the Sceneform UX package to make common AR tasks easier.
*/
public class MainActivity extends AppCompatActivity
private static final String TAG = MainActivity.class.getSimpleName();
private static final double MIN_OPENGL_VERSION = 3.1;
Session mSession;
private ArFragment arFragment;
private ArSceneView arSceneView;
private ModelRenderable andyRenderable;
private boolean shouldConfigureSession = false;
private boolean modelAdded = false;
private ObjectAnimator objectAnimation;
private TransformableNode andy;
private AnchorNode endNode;
private GestureDetector trackableGestureDetector;
/**
* Returns false and displays an error message if Sceneform can not run, true if Sceneform can run
* on this device.
* <p>
* <p>Sceneform requires android N on the device as well as OpenGL 3.1 capabilities.
* <p>
* <p>Finishes the activity if Sceneform can not run
*/
public static boolean checkIsSupportedDeviceOrFinish(final Activity activity)
if (Build.VERSION.SDK_INT < VERSION_CODES.N)
Log.e(TAG, "Sceneform requires Android N or later");
Toast.makeText(activity, "Sceneform requires Android N or later", Toast.LENGTH_LONG).show();
activity.finish();
return false;
String openGlVersionString =
((ActivityManager) activity.getSystemService(Context.ACTIVITY_SERVICE))
.getDeviceConfigurationInfo()
.getGlEsVersion();
if (Double.parseDouble(openGlVersionString) < MIN_OPENGL_VERSION)
Log.e(TAG, "Sceneform requires OpenGL ES 3.1 later");
Toast.makeText(activity, "Sceneform requires OpenGL ES 3.1 or later", Toast.LENGTH_LONG)
.show();
activity.finish();
return false;
return true;
@Override
@SuppressWarnings("AndroidApiChecker", "FutureReturnValueIgnored")
// CompletableFuture requires api level 24
// FutureReturnValueIgnored is not valid
protected void onCreate(Bundle savedInstanceState)
super.onCreate(savedInstanceState);
if (!checkIsSupportedDeviceOrFinish(this))
return;
setContentView(R.layout.activity_main);
ActivityCompat.requestPermissions(this, new String[]Manifest.permission.READ_EXTERNAL_STORAGE, 105);
arFragment = (ArFragment) getSupportFragmentManager().findFragmentById(R.id.ux_fragment);
if (arFragment != null)
arFragment.getPlaneDiscoveryController().hide();
arFragment.getPlaneDiscoveryController().setInstructionView(null);
arSceneView = arFragment.getArSceneView();
arSceneView.getScene().addOnUpdateListener((this::onUpdateFrame));
arFragment.getArSceneView().getScene().addOnPeekTouchListener(this::handleOnTouch);
this.trackableGestureDetector = new GestureDetector(this, new GestureDetector.SimpleOnGestureListener()
public boolean onSingleTapUp(MotionEvent e)
onSingleTap(e);
return true;
public boolean onDown(MotionEvent e)
return true;
);
// When you build a Renderable, Sceneform loads its resources in the background while returning
// a CompletableFuture. Call thenAccept(), handle(), or check isDone() before calling get().
File file = new File(Environment.getExternalStorageDirectory(), "model.sfb");
Uri photoURI = Uri.fromFile(file);
Callable callable = () -> (InputStream) new FileInputStream(file);
FutureTask task = new FutureTask<>(callable);
new Thread(task).start();
ModelRenderable.builder()
.setSource(this, R.raw.model) //.setSource(this, callable)
.build()
.thenAccept(renderable -> andyRenderable = renderable)
.exceptionally(
throwable ->
Toast toast =
Toast.makeText(this, "Unable to load andy renderable", Toast.LENGTH_LONG);
toast.setGravity(Gravity.CENTER, 0, 0);
toast.show();
return null;
);
arFragment.setOnTapArPlaneListener(
(HitResult hitResult, Plane plane, MotionEvent motionEvent) ->
if (andyRenderable == null)
return;
if (modelAdded)
endNode = new AnchorNode(hitResult.createAnchor());
endNode.setParent(arFragment.getArSceneView().getScene());
startWalking();
);
private void handleOnTouch(HitTestResult hitTestResult, MotionEvent motionEvent)
// First call ArFragment's listener to handle TransformableNodes.
arFragment.onPeekTouch(hitTestResult, motionEvent);
// Check for touching a Sceneform node
if (hitTestResult.getNode() != null)
return;
// Otherwise call gesture detector.
trackableGestureDetector.onTouchEvent(motionEvent);
private void onSingleTap(MotionEvent motionEvent)
Frame frame = arFragment.getArSceneView().getArFrame();
if (frame != null && 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()))
Plane plane = (Plane) trackable;
endNode = new AnchorNode(plane.createAnchor(plane.getCenterPose()));
endNode.setParent(arFragment.getArSceneView().getScene());
startWalking();
// Handle plane hits.
break;
else if (trackable instanceof Point)
// Handle point hits
Point point = (Point) trackable;
endNode = new AnchorNode(point.createAnchor(hit.getHitPose()));
endNode.setParent(arFragment.getArSceneView().getScene());
startWalking();
else if (trackable instanceof AugmentedImage)
// Handle image hits.
AugmentedImage image = (AugmentedImage) trackable;
endNode = new AnchorNode(image.createAnchor(image.getCenterPose()));
endNode.setParent(arFragment.getArSceneView().getScene());
startWalking();
private void startWalking()
objectAnimation = new ObjectAnimator();
objectAnimation.setAutoCancel(true);
objectAnimation.setTarget(andy);
// All the positions should be world positions
// The first position is the start, and the second is the end.
objectAnimation.setObjectValues(andy.getWorldPosition(), endNode.getWorldPosition());
// Use setWorldPosition to position andy.
objectAnimation.setPropertyName("worldPosition");
// The Vector3Evaluator is used to evaluator 2 vector3 and return the next
// vector3. The default is to use lerp.
objectAnimation.setEvaluator(new Vector3Evaluator());
// This makes the animation linear (smooth and uniform).
objectAnimation.setInterpolator(new LinearInterpolator());
// Duration in ms of the animation.
objectAnimation.setDuration(500);
objectAnimation.start();
private void configureSession()
Config config = new Config(mSession);
if (!setupAugmentedImageDb(config))
Toast.makeText(this, "Could not setup augmented", Toast.LENGTH_SHORT).show();
config.setUpdateMode(Config.UpdateMode.LATEST_CAMERA_IMAGE);
mSession.configure(config);
@Override
public void onPause()
super.onPause();
if (mSession != null)
// Note that the order matters - GLSurfaceView is paused first so that it does not try
// to query the session. If Session is paused before GLSurfaceView, GLSurfaceView may
// still call session.update() and get a SessionPausedException.
arSceneView.pause();
mSession.pause();
@Override
protected void onResume()
super.onResume();
if (mSession == null)
String message = null;
Exception exception = null;
try
mSession = new Session(this);
catch (UnavailableArcoreNotInstalledException
e)
message = "Please install ARCore";
exception = e;
catch (UnavailableApkTooOldException e)
message = "Please update ARCore";
exception = e;
catch (UnavailableSdkTooOldException e)
message = "Please update this app";
exception = e;
catch (Exception e)
message = "This device does not support AR";
exception = e;
if (message != null)
Toast.makeText(this, message, Toast.LENGTH_SHORT).show();
Log.e(TAG, "Exception creating session", exception);
return;
shouldConfigureSession = true;
if (shouldConfigureSession)
configureSession();
shouldConfigureSession = false;
arSceneView.setupSession(mSession);
private void onUpdateFrame(FrameTime frameTime)
Frame frame = arSceneView.getArFrame();
Collection<AugmentedImage> updatedAugmentedImages =
frame.getUpdatedTrackables(AugmentedImage.class);
Log.d("size----", String.valueOf(updatedAugmentedImages.size()));
for (AugmentedImage augmentedImage : updatedAugmentedImages)
if (augmentedImage.getTrackingState() == TrackingState.TRACKING)
// Check camera image matches our reference image
if (augmentedImage.getName().contains("car"))
if (!modelAdded)
modelAdded = true;
Anchor anchor = augmentedImage.createAnchor(augmentedImage.getCenterPose());
AnchorNode anchorNode = new AnchorNode(anchor);
anchorNode.setParent(arFragment.getArSceneView().getScene());
// Create the transformable andy and add it to the anchor.
andy = new TransformableNode(arFragment.getTransformationSystem());
andy.setParent(anchorNode);
andy.setRenderable(andyRenderable);
andy.select();
private boolean setupAugmentedImageDb(Config config)
AugmentedImageDatabase augmentedImageDatabase;
Bitmap augmentedImageBitmap = loadAugmentedImage();
if (augmentedImageBitmap == null)
return false;
augmentedImageDatabase = new AugmentedImageDatabase(mSession);
augmentedImageDatabase.addImage("car", augmentedImageBitmap);
config.setAugmentedImageDatabase(augmentedImageDatabase);
return true;
private Bitmap loadAugmentedImage()
try (InputStream is = getAssets().open("car.jpeg"))
return BitmapFactory.decodeStream(is);
catch (IOException e)
Log.e(TAG, "IO exception loading augmented image bitmap.", e);
return null;
【讨论】：
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