URP water reflection artifacts / lines on iOS

[antja0]

Reported originally on discord

Observations:

• only happens in iOS build, not in mac editor (unless I disable Reflection Probes > Probe blending)
• noticed when I disable Reflection Probes > Probe blending from URP settings, I can see similar artifacts also on editor. Although at different distances. on iOS build they appear when I'm close to the water, in editor they appear when I'm far away from the water
• it's only reflections - does not happen if water material reflection occlusion is 0

Do you know what could be causing this or how could I start debugging this issue? Are there any settings / things you’d want me to try?

https://github.com/user-attachments/assets/3a3cdc44-90d0-4066-af59-df8798723f59

Unity Version

6000.0.43f1

Crest Version

5.4.2

Render Pipeline

Universal

Editor or Standalone

Standalone

Environment

- Graphics API: Metal
- Target Platform: iOS

[antja0]

I might have found a solution by changing:

MaximumHorizontalDisplacement 15 -> 100

in WaveHarmonic.Crest.ShapeFFT

absolutely no idea why this works, I was just going through settings 😅

[antja0]

the solution above did not work in all cases.

unfortunately we gave up on Crest and developed our own custom water shader instead.

I won't be following this issue anymore

[magenta404]

No worries. Sorry to see you go.

I have marked this as a Unity bug (possibly platform limitation). It's likely probe blending is not working correctly on iOS. We will investigate this at some point.

Thank you for reporting.