Error 'getHitTestResults' on 'XRFrame': Unable to obtain hit test results for specified hit test

🌵 Needle Engine
1

With the attached script, in entry of WebXR on Android, I can get the hitTestResults, but when I exit and re-enter WebXR AR after, I get this error below and I can’t access the hitTestResults?

{"stack": "Error: Failed to execute 'getHitTestResults' on 'XRFrame': Unable to obtain hit test results for specified hit test source. Ensure that it was not already canceled.\n    at WebXRInterface.onUpdate

WebXRInterface.ts

Original Post on Discord

by user 103054507105067008

2

Is there a way to check if an XRHitTestSource has been cancelled before I get the hitTestResults?

  onUpdate(session: XRSession, frame: XRFrame) {
    //console.log("hittestsouurce: ",this.hitTestSource);
    if (!this.hitTestSource) return;
    //console.log("update");
    const hitTestResults = frame.getHitTestResults(this.hitTestSource);
    if (hitTestResults.length) {

by user 103054507105067008

3

Mh so a note: when using onBeforeRender it is the xrFrame that we get from three.js. I’m not sure why it should be cancelled / not work anymore the second time (we use it as well when placing the Reticle)

Just for testing: do you get the same result with this.context.xrFrame ? It should be the same object tho so lead to the same result, just to be sure

4

Same issue there when I try

    const hitTestResults = this.context.xrFrame?.getHitTestResults(
      this.hitTestSource
    );

by user 103054507105067008

5

could it be caused by the hitTestSource being re-used?

6

at least for a few frames?

7

since it is deferred and the second time you enter XR you still have the source from the session before
image.png

8

so this might fix it
image.png

9

Hell yeah that worked! Thankyou so much!

by user 103054507105067008

10

Was probably a silly mistake on my part but I wasn’t sure if the source was reused

by user 103054507105067008

11

Nice! Happy to hear