android - 如何在 ARCore 的 Sceneform 中的两个 anchor 之间画线？

Question

我想在 ArFragment 的 Sceneform 上用一些可见的线连接两个 TransformableNode，但不使用 OpenGL 函数。是否可以在 Android 中的 ARCore Java 中的 Sceneform 中的两个 anchor (或节点)之间画一条线？如果可能的话，我该怎么做？

Answer 1

是的，有一种方法可以做到这一点:

private void addLineBetweenHits(HitResult hitResult, Plane plane, MotionEvent motionEvent) {

    int val = motionEvent.getActionMasked();
    float axisVal = motionEvent.getAxisValue(MotionEvent.AXIS_X, motionEvent.getPointerId(motionEvent.getPointerCount() - 1));
    Log.e("Values:", String.valueOf(val) + String.valueOf(axisVal));
    Anchor anchor = hitResult.createAnchor();
    AnchorNode anchorNode = new AnchorNode(anchor);


    if (lastAnchorNode != null) {
        anchorNode.setParent(arFragment.getArSceneView().getScene());
        Vector3 point1, point2;
        point1 = lastAnchorNode.getWorldPosition();
        point2 = anchorNode.getWorldPosition();

    /*
        First, find the vector extending between the two points and define a look rotation
        in terms of this Vector.
    */
        final Vector3 difference = Vector3.subtract(point1, point2);
        final Vector3 directionFromTopToBottom = difference.normalized();
        final Quaternion rotationFromAToB =
                Quaternion.lookRotation(directionFromTopToBottom, Vector3.up());
        MaterialFactory.makeOpaqueWithColor(getApplicationContext(), new Color(0, 255, 244))
                .thenAccept(
                        material -> {
                            /* Then, create a rectangular prism, using ShapeFactory.makeCube() and use the difference vector
                                   to extend to the necessary length.  */
                            ModelRenderable model = ShapeFactory.makeCube(
                                    new Vector3(.01f, .01f, difference.length()),
                                    Vector3.zero(), material);
                            /* Last, set the world rotation of the node to the rotation calculated earlier and set the world position to
                                   the midpoint between the given points . */
                            Node node = new Node();
                            node.setParent(anchorNode);
                            node.setRenderable(model);
                            node.setWorldPosition(Vector3.add(point1, point2).scaled(.5f));
                            node.setWorldRotation(rotationFromAToB);
                        }
                );
        lastAnchorNode = anchorNode;
    }
}