Issue with POINTERDOUBLETAP and Flutter

Questions
1

Hi folks,

At Smplrspace, we have a Babylon-based 3D viewer that other software companies integrate into their applications. It’s been used in prod for 3 years and today we’ve got an issue reported for the first-time where the POINTERDOUBLETAP event doesn’t seem to work on a mobile app that’s built with Flutter. The mobile web version (on React) works well, and the Flutter-based mobile app is generally fine, except for POINTERDOUBLETAP that doesn’t seem to respond.

Has anyone come across this problem? Any thoughts on where this might come from? As we’re not Flutter (or mobile) devs ourselves, we’re a bit at a loss here, and I was hoping that this might light a bulb :bulb: in someone else’s head here, and we could get some pointers.

In case it helps, they use the Flutter sdk 3.29.0, release date 12/2/2025.

Thanks,
Thibaut

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cc @amoebachant

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Hi @tibotiber,
I’m also not familiar with Flutter, sorry, this doesn’t spark a light bulb. Is it possible to get a repro from your partner? I wonder if Flutter is intercepting any of the pointer events, but without a repro I can’t test that hypothesis.

Thanks!

4

I’ll see if they’re able to provide that. Thanks for the response.

1 Like
5

I’m back. So we could not create a repro, but I’ve got a pretty singular behavior that I think might spark some ideas. Here is a video:

The first half of the video shows a webview embedded in the flutter based app, that webview has a div on top and a canvas at the bottom (this url). Each of them react to a double tap by changing the color. As you can see, the double tap works in the middle but not on the edges.

The second half shows a webview embedded in the flutter based app, that webview has the babylon-base viewer. Double tap is used to recenter the camera. As you can see, the double tap works on the edges, but not in the middle. So that’s the opposite.

We’ve also added logs when doubleclick is received by the document in the webview, when it receives it (in the center), the 3D scene doesn’t, but on the edges, no logs appear and the 3D scene reacts.

So basically, when the html elements receive the doubleclick, the scene doesn’t and vice-versa.

This happens only for doubleclick, single clicks and dragging are normal. This only happens on iOS.

The webview is integrated into the Flutter app with GitHub - pichillilorenzo/flutter_inappwebview: A Flutter plugin that allows you to add an inline webview, to use a headless webview, and to open an in-app browser window.. We’ve opened an issue on that repo (here).

It doesn’t seem to come from BJS, but it has a strange “inverse” behavior I can’t explain. I’d be really happy if anyone has an idea, or knows someone who’s deep in Flutter and might have an idea.

Thanks