UI-Buttons have lag / unsresponsiveness with WebAR


Iam building an AR-APP in WebAR with facial tracking.

I placed some buttons (PNG planes) which trigger an action via “on tap”. While working perfectly on my Desktops Chrome Browser, my Android Chrome Browser is quit unresponsive to the buttons. You have to press them for a longer time to trigger them. A usual short tap is mostly ignored, so you have to tap several times to trigger them or one long time. Is there a way to fix that ? Maybe a different event I can script ?
I use google Chrome v83 on Desktop and Mobile.

The issue also happens with the tutorials Photobooth App:

So it should be straightforward to reproduce.

Thanks and keep the great work up!


Hi @artur.lohrer,

Thank you for the kind words.

The AR photobooth is quite a heavy experience as it includes 8 or so fully textured 3D models, as well as face tracking. Launching it in WebAR uses the browser hardware to do the calculations and this is probably why we are seeing a decrease in performance.

It would be great if you could get in contact with support@zappar.com and send us the ZPP you are testing so we can do some tests our end to make sure this isn’t an issue with our WebAR platform.

I’ll report back our findings on this forum post.



Hi George,
thanks for your reply!
I sent the zpp-file over.
However, I fear the issue is more connected to the face tracking than to the used 3D-Models.

Is there a way to make the Face-Tracking less ressource hungry ? Maybe set the minimal face size to a higher value or exchange performance for speed ? I do not fear some scripting if you can point me in the right direction of documentation / examples.

Could a different User-Interface, maybe swipe-based instead of tapping help out ?
Maybe even something based on blinks (eye-based) ?