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XRView: isFirstPersonObserver property

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

The XRView interface's read-only isFirstPersonObserver property is a boolean indicating if the XRView is a first-person observer view.

To create video recordings of AR device cameras, you can't simply use one of the rendered eyes, as there often will be a physical offset. Some devices expose a secondary view, the first-person observer view, which has an eye of none.

To receive a first-person observer view, you need to enable the "secondary-views" feature descriptor explicitly (typically as an optional feature). See XRSystem.requestSession() for details.

The isFirstPersonObserver property then allows you to check which secondary view is a first-person observer view.

Examples

Checking for first-person observer views

js

// Make sure to enable "secondary-view"
navigator.xr
  .requestSession("immersive-ar", {
    optionalFeatures: ["secondary-views"],
  })
  .then((session) => {
    // …

    session.requestAnimationFrame((frame) => {
      const views = frame.getViewerPose(space);
      // Make sure to iterate over all views
      for (const view of views) {
        if (view.isFirstPersonObserver) {
          renderFPO();
        } else {
          render();
        }
      }
    });
  });

Specifications

Browser compatibility

Desktop Mobile
Chrome Edge Firefox Internet Explorer Opera Safari WebView Android Chrome Android Firefox for Android Opera Android Safari on IOS Samsung Internet
isFirstPersonObserver
86Always returns false since no headset with first-person view is supported.
86Always returns false since no headset with first-person view is supported.
No No
72Always returns false since no headset with first-person view is supported.
No No
86Always returns false since no headset with first-person view is supported.
No
61Always returns false since no headset with first-person view is supported.
No
13.0Always returns false since no headset with first-person view is supported.

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https://developer.mozilla.org/en-US/docs/Web/API/XRView/isFirstPersonObserver