In at least the 0.4 Fabric API for 1.17.1, there appears to be issues with either shadows or ambient occlusion in specific situations using tinted glass.

Setup:
For my setup, I'm running Minecraft 1.17.1, Fabric Loader 11.6 and only 0.4 Fabric API with no resource packs.

This is an example of it working as expected with FAPI

However, in this arrangement, there are clear lines where there shouldn't be, it should be smooth.

Are you using 0.40.1 or 0.40.0? If 0.40.1 can you try 0.40.0 and see if the resolves the issue?

This is FAPI 0.40.1

alt angle

edit: reshot in daylight

This is 0.40.0+1.17, I can try with 0.40.1 and post some SS for comparison

Ah, ok. The reason I ask is 0.40.1 had a rendering related change (#1701) and want to make sure that its not caused by that.

I couldn't reproduce this issue with Fabric API 0.40.1. What does it look like in vanilla? Could it be hardware-dependent?

	Vanilla	Indigo
Square
Staircase

As you can see, I have this issue as well. I am using an M1 Mac, and Fabric API 0.40.1.

Sorry, I've been busy IRL.

Could it be hardware-dependent?

It might be possible that it's hardware dependant, but don't take my opinion, I have no idea how any of the Fabric API works lmao

	Vanilla	Indigo
Square
Staircase

I'll also leave a copy of my logs and a clear F3 screenshot as well as my driver versions
latest.log

edit: included driver versions from Radeon Software

Issue persists in FAPI 0.40.6, any new developments or at least any luck in reproducing?