Unity Issue Tracker - Texture2D.PackTextures causes mips 7-9 to turn pink/white when packed textures are of ASTC 4x4 compression

Fixed

6.3.X

6.2.X

6.0.X

Won't Fix

6.1.X

2022.3.X

Compressed texture atlases no longer produce invalid mipmaps for smaller atlas items by limiting the number of miplevels. This is based on the miplevel where the smallest atlas item is exactly one compression block large. To work around potential GPU texture sampling performance issues: try grouping items of similar sizes together in different atlasses to limit the amount of atlas items with a fairly large smallest miplevel.

Cancelling 6.1 port as this version of Unity is reaching end-of-life very soon, a backport would not make it in time anymore.

With 2022.3 being in Extended LTS, backporting this could end up bringing more pain than it would solve by breaking existing projects that rely on the existing behaviour and / or potentially affecting performance. As such, at this time, we are opting to close this port out as "Won't Fix".

How to reproduce:
1. Open the “MipsBug.zip“ project
2. Open the “SampleScene“
3. Change the Platform to Android
4. Enter Play Mode
5. Select the “Terrain“ GameObject in the Hierarchy
6. Find and double-click the “Test Texture“ Texture field at the bottom of the Inspector
7. Change the Mip levels in the Preview in the Inspector
8. Observe the Preview

Expected result: All mips are rendered correctly
Actual result: mips 7-9 are rendered either in pink or white

Reproducible in: 2022.3.58f1, 6000.0.39f1, 6000.1.0b7, 6000.2.0a4

Reproduced on: Windows 11 Pro (23H2)
Not reproduced on: No other environment tested

Notes:

The Android platform has to be active for the images to be in ASTC 4x4 compression format
After 2023.2.0a5, behaviour differs between the editor and the player: instead of mips 7-9 always being pink/purple, the mentioned mips become white in the editor exclusively.
If empty space is left after packing, "background color" is the same as the color seen in mips 7-9.

Texture2D.PackTextures causes mips 7-9 to turn pink/white when packed textures are of ASTC 4x4 compression

Unity: Texture

Fixed

Won't Fix

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Have a workaround or additional info about this issue?

Texture2D.PackTextures causes mips 7-9 to turn pink/white when packed textures are of ASTC 4x4 compression

Unity: Texture

Statuses

Fixed

Won't Fix

Resolution Notes

6.1.XWon't FixCancelling 6.1 port as this version of Unity is reaching end-of-life very soon, a backport would not make it in time anymore.

Description

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Have a workaround or additional info about this issue?