Alembic uv export/load issue
Closed, ResolvedPublic

Description

System Information
win 7 x64

Blender Version
Broken: hash: 62a2ed9

Short description of error
Loading an alembic exported from blender(especcially those objects) doesn`t loads uvs, in blender or 3dsmax (didn`t test other softwares)
in blender in order to load the uvs a need to do a weird procedure, in 3dsmax im looking for a solution to proper load them.

Exact steps for others to reproduce the error


Export those two objects to an .abc file

2-open other blender instance and import the alembic file.
3- check for uvs


4- add a mesh secuencer chache and select the proper object to load

5-apply the modifier

6- select objects to check if any has uvs. .
7-Undo - now the uvs are load but not the modifier that we apply two steps ago

Kévin Dietrich (kevindietrich) triaged this task as Confirmed priority.Dec 11 2016, 10:16 PM

Will check on it a bit later.

@Kévin Dietrich (kevindietrich) this was introduced on rB753edafc . The problem seems to be at read time only, not on writing.

i did more tests on a 3dsmax, importing from file import does not read the uvs, but importing object by object creating the primitive (alembic can be created as a primitive like a cube, click alembic on prim select the path the object click on the scene) it does read the uvs, also created rotated 90º but that its a max thing ^^
So it seem that yep the uvs are there, didn't try to export and import alembic on max to max, to check if its a soft thing or an alembic thing

Checking 2.79RC1 I still can't get the UVs for my example files to load. T51820 Alembic sequence Crash

With 2.79RC1 it works just fine on my machine (Ubuntu Linux). In step 7 you may need to undo twice to get the modifier back, though, but after step 3 the UVs are loaded and stay loaded.

mmmhh, doesn't work for me, but probably I'm just doing it wrong. But if that's the final workflow for the Blender 2.7x branch I'd better go and try again...

b1a036861ddd changed the way we read UVs, so this may be fixed too. Can you re-check?

Sybren A. Stüvel (sybren) lowered the priority of this task from Confirmed to Incomplete.Dec 22 2017, 2:37 PM

I just tried with the latest buildbot version (c66983c). It's not working for me :/

Works just fine here. These are the UVs after exporting the mesh and importing into a new Blender file. I'm simply using Space → Export Alembic and Space → Import Alembic, nothing fancy.

Which steps are you using that don't work? How do you define "not working"?

I tried my testfiles that I mentioned earlier in this thread. You can get them from here: https://developer.blender.org/T51820
They come from Houdini and load fine with UVs into other applications (e. g. gaffer)

Philipp Oeser (lichtwerk) raised the priority of this task from Incomplete to Confirmed.Jan 8 2018, 7:48 PM

@Sybren A. Stüvel (sybren) : I can confirm that files from this report work as expected now, but also seeing that the ones @Thomas Volkmann (knekke) mentioned in T51820: Alembic sequence Crash dont load UVs (note: these have changing topology - fluids - not sure this is a known limitation?)
Also: should we open another report for this? (tagging as confirmed again for the time being...)

@Philipp Oeser (lichtwerk) if the problem in this ticket is solved for the files used to demonstrate the problem, let's close this report. Loading UVs for files with changing topology is indeed something else; could you write a report for that and assign it to me?