engine/docs/en/xr/features.md

order, title, type, label

order	title	type	label
6	XR Abilities	XR	XR

Galacean XR currently includes the following abilities:

Ability	Explanation
Anchor Tracking	Anchor tracking
Plane Tracking	Plane tracking
Image Tracking	Image tracking
Hit Test	Hit test

Anchor Tracking

Property	Explanation
trackingAnchors	(Read-only) Get anchors requested for tracking
trackedAnchors	(Read-only) Get tracked anchors

Method	Explanation
addAnchor	Add a specific anchor
removeAnchor	Remove a specific anchor
clearAnchors	Remove all anchors
addChangedListener	Add a function to listen for anchor changes
removeChangedListener	Remove a function listening for anchor changes

You can add anchors in XR space with the following code:

const anchorTracking = xrManager.getFeature(XRAnchorTracking);
const position = new Vector3();
const rotation = new Quaternion();
// 添加一个锚点
const anchor = anchorTracking.addAnchor(position, rotation);
// 移除这个锚点
anchorTracking.removeAnchor(anchor);
// 监听锚点变化
anchorTracking.addChangedListener(
  (
    added: readonly XRAnchor[],
    updated: readonly XRAnchor[],
    removed: readonly XRAnchor[]
  ) => {
    // 此处添加对新增锚点，更新锚点和移除锚点的处理
  }
);

Plane Tracking

Property	Explanation
detectionMode	(Read-only) Type of planes being tracked, horizontal, vertical, or all
trackedPlanes	(Read-only) Get tracked planes

Method	Explanation
addChangedListener	Add a function to listen for plane changes
removeChangedListener	Remove a function listening for plane changes

Note that when adding functionality to plane tracking, you need to specify the type of plane tracking.

// Specify plane tracking type as all during initialization
xrManager.addFeature(XRPlaneTracking, XRPlaneMode.EveryThing);

We can track real-world planes and mark them with transparent grids and coordinate systems:

Image Tracking

Property	Explanation
trackingImages	(Read-only) Array of images requested for tracking, including name, source, and size
trackedImages	(Read-only) Get tracked images

Method	Explanation
addChangedListener	Add a function to listen for image changes
removeChangedListener	Remove a function listening for image changes

Note that when adding functionality to image tracking, you need to specify the images to track, and in WebXR, each image will only be tracked once.

// Specify the images to track during initialization
xrManager.addFeature(XRImageTracking, [refImage]);

We can track real-world images and mark them with coordinate systems:

Collision Detection

Method	Description
hitTest	Collision detection by casting rays in real space
screenHitTest	Collision detection by comparing screen space coordinates with real space planes

const pointer = engine.inputManager.pointers[0];
// 获取平面触控点
if (pointer) {
  const hitTest = xrManager.getFeature(XRHitTest);
  const { position } = pointer;
  // 通过屏幕空间坐标与现实空间的平面进行碰撞检测
  const result = hitTest.screenHitTest(
    position.x,
    position.y,
    TrackableType.Plane
  );
}