deboisj
(Julien Deboise)
August 28, 2023, 6:20pm
1
Hello,
I am in the process of updating the USD version we use in the 3dsMax USD plugin.
I am noticing there must have been some schema change in UsdSkel :
This is the UsdSkel sample, that I had locally (so build in an earlier USD version, I am not quite sure which, most likely 21.X, displayed in 23.08).
Looking at the hydra scene, it seems that some prims are just missing the “skinningComputation” :
Initially i was thinking some regression in USD, as this file showed fine in 22.11, but then re-downloaded the sample from UsdSkel Examples — Universal Scene Description 23.08 documentation , and that version works ok in 23.08
Looking at the release notes, I dont see anything obvious that would explain this (?)
Is this expected? What there a schema change that would prevent older files to no longer work in 23.08?
Many thanks,
Julien
deboisj
(Julien Deboise)
August 28, 2023, 6:33pm
2
I believe I have figured out the problem, by diffing the files as ASCII.
The previous version of the sample didnt have the SkelBindingApi applied on all the prims using usdskel. I guess USD is a bit more strict now…
I think you’re right. I brought up this related issue about another UsdSkel example where Spiff confirms your suspicion.
Relevant snippet from the 23.05 CHANGELOG:
Added compliance tests to make sure UsdSkelBindingAPI is applied on prims having properties provided by UsdSkelBindingAPI. Also added a compliance test to ensure that UsdSkelBindingAPI has only been applied on SkelRoot prims or descendants of SkelRoot prims.
spiff
(F Sebastian Grassia)
August 28, 2023, 9:03pm
4
23.08 became strict about requiring SkelBindingAPI to be applied. Note that the updated Skel example on OpenUSD.org is 100% backwards compatible with earlier releases.