Massive visual glitches on Android

LyubomirIko · September 1, 2026, 3:16am

Samsung Galaxy A15 / Android 16

If I use even slightly “Brightness and contrast” effect I am getting those:

The game don’t have performance issues during this… thing.

DesmonDev · September 1, 2026, 4:56am

yes its horrifying i know

LyubomirIko · September 1, 2026, 5:39pm

It’s a known issue then? I am getting the glitch even without Brightness and contrast" effect actually, although just in places. I don’t know what triggers it, sometimes it’s the bright spots, but sometimes it’s the dark spots. Seems like somewhere in the code the values of the tonemap are not kept clamped and overflow or something like that…

DesmonDev · September 1, 2026, 5:50pm

for me it happens with really any 3d effect other than i think bloom

Clement · September 3, 2026, 7:59am

Hello @LyubomirIko

Thanks for the report. Could you help narrow this down with a quick test?

In the Project Manager, open Game settings > Properties. Find the Antialiasing for 3D dropdown and set it to Never (not “Not on mobile”, that one still keeps part of the antialiasing on phones).
Tell us whether the glitches are gone, unchanged, or different, with a screenshot if possible?

It would also help to know:

Which GDevelop version you are using.
Whether the glitch still shows with every 3D effect removed from all layers, since you mentioned seeing it in places without the effect.
If you can share a small project that reproduces it.

Thanks

LyubomirIko · September 3, 2026, 8:57am

I am on the latest version. Turning Antialiasing off/on, doesn’t fix it. I just created a new project from a template, I add those values; and I move around; nothing else. I don’'t see a point of sharing that file, it’s very easy to reproduce? But if you insist, I will.

It’s mostly in the shadows/darks, but sometimes it is in reverse, so if there is bright light it will happen. The Bloom effect seems to help with this happening in the light. The Hue and Saturation alone too can have effect. It seems depending on the overall brightness of the scene. Putting a Direct light can decrease the glitch, but doesn’t help removing it as in the example above.

Clement · September 3, 2026, 10:05am

Thanks for the info and screenshots.
I assume it’s related to the Android device, which is why I cannot reproduce.

In order to help me investigate, can you try those settings:

Brightness 0.19, contrast 0.4. → you should still see the glitch
Brightness 0.21, contrast 0.4 → you should not see the glitch any more

Let me know if that’s the case or not.
Thanks

LyubomirIko · September 3, 2026, 11:18am

Actually I can’t see it on Brightness 0.19, contrast 0.4

Or at least on that scene. I have a gut feeling the textures are not dark enough. Dark textures are extra affected.

But if I introduce + Hue 0 Saturation 0.2 - I can see it with Brightness 0.19, contrast 0.4.

Also if I introduce a little more: Saturation 0.8 - I see it with Brightness 0.21, contrast 0.4 too.

Here:

I am building the .apk files on my rig with Cordova terminal if this could be somehow related. When messing with those effects I don’t seek so wash out colours. More brightness could fix the issue, but makes the whole existence of this effect useless with mobile.

Clement · September 3, 2026, 11:36am

Thanks for the details!

OK, my intuition is that the effect pushes a color’s value below zero, which is poorly handled by your device’s GPU.
I’ll try a fix and build an experimental GDevelop installer for you to test if that’s OK?
Are you using Windows?