[EMSUSD-1798] export visibility from abc

[kimuss]

Describe the bug
export does not read visibility channel

Steps to reproduce
Steps to reproduce the behavior:

1. import abc file with a visibility animation
2. usd export selection (or all) and check on visibility in export option
3. create stage from file just created
4. See the visibility does not have animation

Expected behavior
Use the visibility abc channel to write the visibility token on usd export, this work good on maya native element, like this:

Specs (if applicable):

• Windows 11
• Maya 2024.2
• Maya USD plugin 0.30

thank you

[santosg87]

thank you for reporting this!

I can reproduce this as well.

It seems the reason this is failing is due to how the alembic file is imported in maya. Since the animation is kept in the alembic node and not actually on the geometry itself. (when importing alembic, you can see an alembic node is created pointing to the file in disk).

I logged and internal ticket and will bring it to the team to discuss any next steps.

[kimuss]

.. Since the animation is kept in the alembic node and not actually on the geometry itself.

exactly, usd export seems not to consider the link of the alembic node, also with "channel" and "history" checked in the USD export option

thank you

[santosg87]

unfortunately, because there is a link, maya struggles with exporting that data, as the workflows on alembic are made that way to allow for updating the geometry cache if needed, so that node isn't exported.

2 possible workarounds here:

1. bake the animation before exporting - that way you would have actual Keys that would translate on export.
2. a second option - although not very widely used, would be to just reference the alembic file directly on your USD stage, as USD does have some limited support to alembic.

at this time, this issue isn't a high priority, but we will keep it in our backlog for future improvements!

Cheers!