2025.07 Rendering Differences

[bennettgoble]

Environment

Second Life Release 7.2.2.17801718290 (64bit)
Release Notes

CPU: Apple M2 (2400 MHz)
Memory: 16384 MB
OS Version: macOS 26.0.0 Darwin 25.0.0 Darwin Kernel Version 25.0.0: Mon Aug 25 21:17:53 PDT 2025; root:xnu-12377.1.9~3/RELEASE_ARM64_T8112 arm64
Graphics Card Vendor: Apple
Graphics Card: Apple M2

OpenGL Version: 4.1 Metal - 90.5

Window size: 1470x891
Font Size Adjustment: 96pt
UI Scaling: 1
Draw distance: 96m
Bandwidth: 3000kbit/s
LOD factor: 1.125
Render quality: 1
Texture memory: 12124MB
Disk cache: Max size 2150.4 MB (80.8% used)
HiDPI display mode:

J2C Decoder Version: KDU v8.4.1
Audio Driver Version: OpenAL, version 1.1 ALSOFT 1.24.2 / OpenAL Community / OpenAL Soft: OpenAL Soft
Dullahan: 1.21.0.202508272158
CEF: 139.0.28+g55ab8a8+chromium-139.0.7258.139
Chromium: 139.0.7258.139
LibVLC Version: 3.0.21
Voice Server Version:

September 18 2025 18:23:57

Description

2025.07 exhibits differences in render appearance that are unexpected and especially noticeable on avatars:

2025.06

2025.07

Reproduction steps

1. Set sky to mid-day (Easiest to see)
2. Observe clothing/skin

Expected: visual appearance should match prior releases
Actual: Color banding, shading changes are visible

Repro 2

1. Log in at http://maps.secondlife.com/secondlife/Danger!%20Danger!/66/40/38 (a private region)
2. Set sky to Midday (ctrl+shift+y)
3. Teleport to http://maps.secondlife.com/secondlife/By%20Design/116/92/22 (a private region)

Observed: The bottom sides of objects are very dark. Video: https://github.com/user-attachments/assets/469f4362-34ad-477c-ae5e-0a7e617a6e61

Expected: The visual appearance should match 2025.06

Note: There's something in the environment settings at the 2 locations in step 1 and 3 that trigger this bug. You can swap the locations in step 1 and 3 and the bug will repro.

Note 2: A video of a different way to reproduce this. Video: https://github.com/user-attachments/assets/b1e015e6-7859-4e89-a08e-d9788fc3d5aa

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[akleshchev]

There are some shader changes:

1. LEGACY_GAMMA in CASF.glsl 452c8e0
2. GAMMA_CORRECT in postDeferredTonemap.glsl 452c8e0
3. clamp change in postDeferredGammaCorrect.glsl 452c8e0
4. Color changes in SMAA.glsl 24aef9a

[PhilipRosedale]

I didn’t think we had renderer changes in this release?

[akleshchev]

They are apple silicon related.

[Geenz]

Yes - there were some optimizations merged in to try and further improve performance on Apple Silicon. I'm looking into it now.

[Dan-Linden]

These issue reproduce in Windows too.
This bug does not reproduce everywhere as I first suspected. There's something at http://maps.secondlife.com/secondlife/Danger!%20Danger!/66/40/38 and http://maps.secondlife.com/secondlife/By%20Design/116/92/22 that triggers this.
I've updated Repro 2 in the description with a repro that should work 100% of the time.