XRSession: requestHitTestSourceForTransientInput() method

Limited availability

This feature is not Baseline because it does not work in some of the most widely-used browsers.

Experimental: This is an experimental technology
Check the Browser compatibility table carefully before using this in production.

Secure context: This feature is available only in secure contexts (HTTPS), in some or all supporting browsers.

The requestHitTestSourceForTransientInput() method of the XRSession interface returns a Promise that resolves with an XRTransientInputHitTestSource object that can be passed to XRFrame.getHitTestResultsForTransientInput().

Syntax

requestHitTestSourceForTransientInput(options)

Parameters

options

An object containing configuration options, specifically:

profile

A string specifying the input profile name of the transient input source that will be used to compute hit test results.

entityTypes Optional

An Array specifying the types of entities to be used for hit test source creation. If no entity type is specified, the array defaults to a single element with the plane type. Possible types:

point: Compute hit test results based on characteristic points detected.
plane: Compute hit test results based on real-world planes detected.
mesh: Compute hit test results based on meshes detected.

offsetRay Optional

The XRRay object that will be used to perform hit test. If no XRRay object has been provided, a new XRRay object is constructed without any parameters.

Return value

A Promise that resolves with an XRTransientInputHitTestSource object.

Exceptions

Rather than throwing true exceptions, requestHitTestSourceForTransientInput() rejects the returned promise with a DOMException, specifically, one of the following:

NotSupportedError DOMException: Thrown if hit-test is not an enabled feature in XRSystem.requestSession().
InvalidStateError DOMException: Thrown if the session has already ended.
NotAllowedError DOMException: Thrown if there is an unreasonable amount of requests. Some user agents might limit usage for privacy reasons.

To request a hit test source, start an XRSession with the hit-test session feature enabled. Next, configure the hit test source and store it for later use in the frame loop and call XRFrame.getHitTestResultsForTransientInput() to obtain the result.

const xrSession = navigator.xr.requestSession("immersive-ar", {
  requiredFeatures: ["local", "hit-test"],
});

let transientHitTestSource = null;

xrSession
  .requestHitTestSourceForTransientInput({
    profile: "generic-touchscreen",
    offsetRay: new XRRay(),
  })
  .then((touchScreenHitTestSource) => {
    transientHitTestSource = touchScreenHitTestSource;
  });

// frame loop
function onXRFrame(time, xrFrame) {
  let hitTestResults = xrFrame.getHitTestResultsForTransientInput(
    transientHitTestSource,
  );

  // do things with the transient hit test results
}