3ds Max SDK: UV Channel 2 resets after “Abandon”

[MSFS 2024] Bug Reports SDK: Tools/Samples/Documentation
1

  • SDK Version: 1.5.7

  • Frequency: Consistently

  • Severity: Blocker

Bug Description:
In the latest MSFS 3ds Max SDK (and possibly earlier versions), switching to UV Channel 2 triggers the prompt offering two options: Move and Abandon.

Expected behavior:

  • Choosing Abandon should allow switching to UV Channel 2 without moving/copying UV Channel 1 data into Channel 2, so both channels remain independent and editable. This is critical for workflows where UV1 and UV2 must remain separate (e.g., different mapping purposes).

Actual behavior:

  • When selecting Abandon, UV Channel 2 does not persist correctly. After switching away and returning to Channel 2, the UVs on Channel 2 are reset/lost, as if the channel was never saved. This makes it impossible to iteratively author UV2.

Impact / Workaround:

  • The current workaround is to bake the result, but baking is destructive for iteration: if we later need to revisit or refine UV Channel 2, we risk losing prior UV2 work when returning to that channel.

  • This blocks normal production workflows that require repeated edits to UV2 over time and makes multi-channel UV authoring unreliable.

This appears to be an SDK/tooling regression or a broken implementation of the Abandon option and should be fixed so UV Channel 2 is preserved and editable independently after choosing Abandon.

2

I’ve dealt with this exact bug going back to 3dsMax 2008 - the workaround I’ve always used is treat switching to UV2 as ‘one way’; abandon UV1→ edit UV2 as required → collapse stack with UV2 still selected. If you need to go back to UV1 you can re-add the unwrap modifier. It’s not ideal but 3dsMax has a ton of issues with preserving interim data like this, vertex colours, node names etc.

I doubt Asobo has much influence on this from my experience at least.

2 Likes
3

That is exactly what I found works too. Collapse and if you need to make a change then add the UV modifier then abandon to UV2 again.

But this was working several version ago or back in 2020. So for me this is the first time I have ever encountered this.

4

Hello,

This is a 3DS Max issue, so it will need to be reported through Autodesk/3ds Max support.

As a workaround, I think you can use two UVW modifiers instead of switching UVs within a single modifier.

image
image370×266 5.35 KB

Regards,
Boris

1 Like
5

This topic has been automatically closed after 60 days of inactivity since it was marked as obsolete.

If there is important new information about this same report, you can use the “Request reopen” button below to ask the moderation team to review it again.
For other issues or broader discussion, please open a new topic in the appropriate category.