webXR shows "AR session supported" on unsupported device

Describe the bug This phone does not have ar-core support , but the start ar buttons is present & navigator.xr.isSessionSupported('immersive-ar') returns true

but clicking on the button asks camera permissions then crashes (screenshot has error message)

Expected behavior

This device does not support google ar core , so navigator.xr.isSessionSupported('immersive-ar') should return false as AR experiences on Android can only be run on an ARCore supported device.

Screenshots

Platform:

• Device: [Mobile: Samsung galaxy M30]
• OS: [Android]
• Browser: [Chrome]
• Three.js version: [r135]

[jynxio]

Summary

This error comes from WebXR API, not three.js (I think) .

details

Based on my experience, When the test machine meets the following 2 conditions, navigator.xr.isSessionSupported('immersive-ar') will always return true (fulfilled) : ① phone ② https Otherwise it will return false.

When I use a mobile phone (not supporting ARcore) to visit a WebXR site that uses https, the following events will occur in sequence: ① navigator.xr.isSessionSupported('immersive-ar') will return true(fulfilled) ② A pop-up box in the middle of Chrome asks me “whether to grant AR permissions to the site” (If the user has granted this permission to the site, this step will not appear) ③ I allow to grant AR permissions to this site ④ The pop-up box at the bottom of Chrome says “ARCORE needs to be installed” ⑤ I click “install” ⑥ After a short loading animation, the phone jumps to the ARCORE download page of the App store (Some phones may not automatically redirect to the App store, this is most likely because ARCore is not listed on the App Store of this phone, at this time, you can only download ARcore on Google Play by yourself) ⑦ Install ARCore ⑧ The App Store pop-up prompts “The app is not adapted to your device, and abnormal conditions such as freezes and flashbacks may occur during operation. It is recommended to wait for the app developer to solve the adaptation problem before trying to install.” (This is why you see “crashes”) ⑨ Restart the site and start the AR program (immersive-ar) ⑩ crashes

Obviously, this bug (navigator.xr.isSessionSupported('immersive-ar') will always return true on phone that do not support ARCore) comes from the WebXR API. It should not be fixed by modifying three.js, the bug has nothing to do with the device (I think) .

Code

check().then(is_supported => {

    if (!is_supported) {

        button.textContent = "Not Support";

        return;

    }

    button.textContent = "Open";
    button.addEventListener("click", _ => {

        navigator.xr.requestSession("immersive-ar", {}).then(session => {

            renderer.xr.setReferenceSpaceType("local");
            renderer.xr.setSession(session);

        });

    });

});

function check() {

    return (new Promise(function (resolve) {

        const is_support_https = _checkHttps();

        if (!is_support_https) {

            resolve(false);

            return;

        }

       _ checkImmersiveAr().then(resolve);

    }));

};

function _checkHttps() {

    return window.isSecureContext;

}

function _checkImmersiveAr() {

    return (new Promise(function (resolve) {

        if (!("xr" in window.navigator)) {

            resolve(false);

            return;

        }

        navigator.xr.isSessionSupported("immersive-ar").then(resolve);

    }));

}

Most of the code related to “three.js” is omitted

Other

I have a device that supports ARCore, which can run the WebXR application built by the above code normally

[Mugen87]

Closing then. I’m not sure where it’s best to report this issue but the browser vendor might be a good start.