Basic UsdSkel doesn't animate in usdview-23.08

[mati-nvidia]

Description of Issue

usdview-23.08 viewport does not show the animation from this basic UsdSkel example: https://openusd.org/release/api/_usd_skel__schema_overview.html

Steps to Reproduce

1. Save the USDA from Skinning an Arm example: https://openusd.org/release/api/_usd_skel__schema_overview.html
2. Open the USDA file with usdview (23.08)
3. Press play or scrub through the timeline
4. RESULT: The interpolated values for /Model/Skel/Anim.rotations are displayed in the Properties window, but it does not animate in the viewport.

System Information (OS, Hardware)

Windows 10

Package Versions

USD-23.08, Python 3.10

Build Flags

Default

[jesschimein]

Filed as internal issue #USD-8624

[spiffmon]

Oh Shazam, @mati-nvidia - good find, and reinforcement that we need to find time to turn all of our doc examples into unit tests. It looks like when we made the changes to "strictify" the application of SkelBindingAPI, the bindings discovery process lost the ability to find animation bindings inside/under Skeleton prims. If I simply move the skel:animation binding up onto </Model> then all works as expected. We'll get this fixed for 23.11... give a shout if this is a pattern that's being used commonly - looks like we do not use it anywhere except in this example!

[mati-nvidia]

I checked around and, for example, currently our Blender exporter sets the skel:animationSource on the Skeleton prim, but also correctly applies the SkelBindingAPI on the Skeleton prim so it plays fine in usdview.

@spiffmon is there some code change you were planning on making for this issue? If it's just a matter of fixing the example by moving skel:animationSource to the SkelRoot, I can include that in some other doc improvements I'm working on.

[spiffmon]

Oh hah! I *totally* missed that the Skeleton was lacking the schema application.. but sure enough: a) usdchecker complains about it - yay! b) adding it fixes the example. Sure, @mati-nvidia, if you were already making a PR, this would be an appreciated fix.

…

--spiff

On Thu, Aug 31, 2023 at 1:56 PM mati-nvidia ***@***.***> wrote: I checked around and, for example, currently our Blender exporter sets the skel:animationSource on the Skeleton prim, but also correctly applies the SkelBindingAPI on the Skeleton prim so it plays fine in usdview. @spiffmon <https://github.com/spiffmon> is there some code change you were planning on making for this issue? If it's just a matter of fixing the example by moving skel:animationSource to the SkelRoot, I can include that in some other doc improvements I'm working on. — Reply to this email directly, view it on GitHub <#2621 (comment)>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/ABPOU2E3ATQ22ETUGR3G5KDXYD26PANCNFSM6AAAAAA35SVYAA> . You are receiving this because you were mentioned.Message ID: ***@***.***>

[tallytalwar]

usdfixbrokenpixarschemas should also fix the application of UsdSkelBindingAPI: https://github.com/PixarAnimationStudios/OpenUSD/blob/release/pxr/usd/bin/usdfixbrokenpixarschemas/usdfixbrokenpixarschemas.py#L51