iOS 15.4 broke the post processing effects


We are using post process effects (brightness-contrast and hue-saturation) in a project and it looks like the latest Safari update that came with iOS 15.4 broke them:

Do you need a test project to debug?


Ben Z.

Hi @iXperiential,

I can test right now (I will), but are you able to see if there are any errors in the console?

Also can you post a screenshot of what artifacts you are seeing?

For this project:

This is what we get:

Also happens on macOS. Safari 15.4. No errors

Hmm, interesting. @mvaligursky any idea?

It might be linked to this:

I see this on macOS 15.3 (17612. as well … Chrome and Safari. I guess it needs to be investigated, nothing obvious stands out. Can you please create a ticket Issues · playcanvas/engine · GitHub to keep track of it.

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Done. Thanks for looking at it!

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Interestingly, this seems to work fine: PlayCanvas Examples

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Hi @mvaligursky, @Leonidas

We just wanted to add some info on this, we noticed that with Safari 15.4 a lot of our PC projects suddenly stopped working

Eg. On this configurator, the object is rendered correctly only for the first frame, then if the user moves the object as it would normally do, nothing happens in the scene, the object doesn’t move or anything.
No embossing writing (we create it trough scripts once the scene is already rendered, when the end user picks some letters).

No errors related to PC in the console

We tought of an error processing input at first, but playing around with the inspector, we noticed that manually resizing the window, causes weird stuff to appear:

  • A pink background scene
  • The embossing writing magically pops out
  • Moving the object (orbit cam), only moves the writing but not the object

We then tried to open some of the demos from PC Home Page, we found out that a lot of them have rendering problems too

After The Flood


Star Lord

This happens on both, Safari mobile and Desktop with rel 15.4

While testing why some of our models were working and some weren’t at all, independently from the PC release used, we found out that on non-working scenes we used the FXAA.js script

Turning the script off, the projects started working again

Is there a work around for this? A part of us turning off FXAA on every project and re-publish it?
Do you think there will be a PC engine release fixing this soon?

Many thanks in advance!

@Change2 - we have this workaround at the moment and are hoping to release the engine with it this week:

In the meantime, you can just turn off antialiasing for your project - this seems to solve it for us but also other webgl based engines. That’s what the workaround does as well, but only when when it detects browser 15.4


Wow, that was fast!

Thank you! :slight_smile:

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