在 arcore 中绘制线条而不是渲染 Anchor

Question

我是 AR 新手，我正在开发一个使用 ARCore 的应用程序，使用这个 AR-REMOTE-SUPPORT 当我从屏幕上绘制它时，它正在创建默认的 android 锚，我想要线条而不是默认的 android 锚。 我怎样才能做到这一点。

这是在屏幕上放置 Anchors 的函数

public void onDrawFrame(GL10 gl) {
        // Clear screen to notify driver it should not load any pixels from previous frame.
        GLES20.glClear(GLES20.GL_COLOR_BUFFER_BIT | GLES20.GL_DEPTH_BUFFER_BIT);

        if (mSession == null) {
            return;
        }
        // Notify ARCore session that the view size changed so that the perspective matrix and
        // the video background can be properly adjusted.
        mDisplayRotationHelper.updateSessionIfNeeded(mSession);

        try {
            // Obtain the current frame from ARSession. When the configuration is set to
            // UpdateMode.BLOCKING (it is by default), this will throttle the rendering to the
            // camera framerate.
            Frame frame = mSession.update();
            Camera camera = frame.getCamera();

            // Handle taps. Handling only one tap per frame, as taps are usually low frequency
            // compared to frame rate.
            MotionEvent tap = queuedSingleTaps.poll();
            if (tap != null && camera.getTrackingState() == TrackingState.TRACKING) {
                for (HitResult hit : frame.hitTest(tap)) {
                    // Check if any plane was hit, and if it was hit inside the plane polygon
                    Trackable trackable = hit.getTrackable();
                    // Creates an anchor if a plane or an oriented point was hit.
                    if ((trackable instanceof Plane && ((Plane) trackable).isPoseInPolygon(hit.getHitPose()))
                            || (trackable instanceof Point
                            && ((Point) trackable).getOrientationMode()
                            == Point.OrientationMode.ESTIMATED_SURFACE_NORMAL)) {
                        // Hits are sorted by depth. Consider only closest hit on a plane or oriented point.
                        // Cap the number of objects created. This avoids overloading both the
                        // rendering system and ARCore.
                        if (anchors.size() >= 250) {
                            anchors.get(0).detach();
                            anchors.remove(0);
                        }
                        // Adding an Anchor tells ARCore that it should track this position in
                        // space. This anchor is created on the Plane to place the 3D model
                        // in the correct position relative both to the world and to the plane.
                        anchors.add(hit.createAnchor());
                        break;
                    }
                }
            }

            // Draw background.
            mBackgroundRenderer.draw(frame);

            // If not tracking, don't draw 3d objects.
            if (camera.getTrackingState() == TrackingState.PAUSED) {
                return;
            }

            // Get projection matrix.
            float[] projmtx = new float[16];
            camera.getProjectionMatrix(projmtx, 0, 0.1f, 100.0f);

            // Get camera matrix and draw.
            float[] viewmtx = new float[16];
            camera.getViewMatrix(viewmtx, 0);

            // Compute lighting from average intensity of the image.
            final float lightIntensity = frame.getLightEstimate().getPixelIntensity();

            if (isShowPointCloud()) {
                // Visualize tracked points.
                PointCloud pointCloud = frame.acquirePointCloud();
                mPointCloud.update(pointCloud);
                mPointCloud.draw(viewmtx, projmtx);

                // Application is responsible for releasing the point cloud resources after
                // using it.
                pointCloud.release();
            }

            // Check if we detected at least one plane. If so, hide the loading message.
            if (mMessageSnackbar != null) {
                for (Plane plane : mSession.getAllTrackables(Plane.class)) {
                    if (plane.getType() == Plane.Type.HORIZONTAL_UPWARD_FACING
                            && plane.getTrackingState() == TrackingState.TRACKING) {
                        hideLoadingMessage();
                        break;
                    }
                }
            }

            if (isShowPlane()) {
                // Visualize planes.
                mPlaneRenderer.drawPlanes(
                        mSession.getAllTrackables(Plane.class), camera.getDisplayOrientedPose(), projmtx);
            }

            // Visualize anchors created by touch.
            float scaleFactor = 1.0f;

            for (Anchor anchor : anchors) {
                if (anchor.getTrackingState() != TrackingState.TRACKING) {
                    continue;
                }
                // Get the current pose of an Anchor in world space. The Anchor pose is updated
                // during calls to session.update() as ARCore refines its estimate of the world.
                anchor.getPose().toMatrix(mAnchorMatrix, 0);


                // Update and draw the model and its shadow.
                mVirtualObject.updateModelMatrix(mAnchorMatrix, mScaleFactor);
                //mVirtualObjectShadow.updateModelMatrix(mAnchorMatrix, scaleFactor);
                mVirtualObject.draw(viewmtx, projmtx, lightIntensity);
                mVirtualObjectShadow.draw(viewmtx, projmtx, lightIntensity);
            }

            sendARViewMessage();
        } catch (Throwable t) {
            // Avoid crashing the application due to unhandled exceptions.
            Log.e(TAG, "Exception on the OpenGL thread", t);
        }
    }

任何帮助将不胜感激

TIA

Answer 1

在 ARCore 中绘制一条线的一种简单方法是在两个锚点之间创建它。

线条本身通常也是一个 3D 对象。

这是一个经过测试的工作示例，基于此答案中的好方法：https://stackoverflow.com/a/52816504/334402

private void drawLine(AnchorNode node1, AnchorNode node2) {
      //Draw a line between two AnchorNodes (adapted from https://stackoverflow.com/a/52816504/334402)
        Log.d(TAG,"drawLine");
        Vector3 point1, point2;
        point1 = node1.getWorldPosition();
        point2 = node2.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.  */
                            Log.d(TAG,"drawLine insie .thenAccept");
                            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 . */
                            Anchor lineAnchor = node2.getAnchor();
                            nodeForLine = new Node();
                            nodeForLine.setParent(node1);
                            nodeForLine.setRenderable(model);
                            nodeForLine.setWorldPosition(Vector3.add(point1, point2).scaled(.5f));
                            nodeForLine.setWorldRotation(rotationFromAToB);
                        }
                );

    }

您可以在此处查看完整源代码：https://github.com/mickod/LineView