Hey folks.

I've got a ROP Fetch pointing at a Component Output node to save out the various USD files I'm looking to put to disk.

If I manually click the "Save to Disk" button on the Component Output node, it behaves exactly as I would hope:
all the various usd files are saved ( payload, geometry, material, and extra layer ), as well as the thumbnail getting generated.

But when I attempt to do the same thing through TOPs, I get the following error:

Running Houdini 20.5.384 with PID 34776
Loading .hip file 'G:/dev/gitRepos/Arcanacom/common/art/playground/autoImports/topsNodes.hiplc'...
.hip file done loading
ROP node path '/stage/assetBuilder'
ROP type name: 'componentoutput'
ROP source path: 'oplib:/Lop/componentoutput?Lop/componentoutput'
ROP library path: 'F:/Side Effects Software/Houdini 20.5.384/houdini/otls/OPlibLop.hda'
Checking for output parm(s) 'lopoutput' on node '/stage/assetBuilder'
Pressing button 'execute' on node
Error: Cook error in input: /stage/assetBuilder/THUMBNAIL
Error: Invalid source /stage/assetBuilder/has_geo_variants.
(Error: Unable to evaluate expression (
Traceback (most recent call last):
File "<stdin>", line 9, in expression
File "F:\Side Effects Software/Houdini 20.5.384/houdini/python3.11libs\loputils.py", line 3014, in fetchParameterValues
prim = stage.GetPrimAtPath('/HoudiniLayerInfo')
^^^^^^^^^^^^^^^^^^^
AttributeError: 'NoneType' object has no attribute 'GetPrimAtPath'
(/stage/assetBuilder/has_geo_variants/input)).)..
Render failed.
Error: Cook error in input: /stage/assetBuilder/cleanup_files_and_update_thumbnail
Error: Invalid source /stage/assetBuilder/has_geo_variants.
(Error: Unable to evaluate expression (
Traceback (most recent call last):
File "<stdin>", line 9, in expression
File "F:\Side Effects Software/Houdini 20.5.384/houdini/python3.11libs\loputils.py", line 3014, in fetchParameterValues
prim = stage.GetPrimAtPath('/HoudiniLayerInfo')
^^^^^^^^^^^^^^^^^^^
AttributeError: 'NoneType' object has no attribute 'GetPrimAtPath'
(/stage/assetBuilder/has_geo_variants/input)).)..
Failed to save output to file "G:/Art/Kitbash/Dark Fantasy/Houdini/usd/assets/Barrel_A_Main/Barrel_A_Main.usd:SDF_FORMAT_ARGS:format=usda".
Render failed.
Checking for output parm(s) 'lopoutput' on node '/stage/assetBuilder'
PDG_RESULT: 892;-1;G:/Art/Kitbash/Dark Fantasy/Houdini/usd/assets/Barrel_A_Main/Barrel_A_Main.usd;;0

Any idea what I could be doing wrong? Any help would be great appreciated! Thanks!

If I go to line 3014 in loputils.py and make sure to check to see if the stage is None and return if so, I'm able to save all my USDs but none of the thumbnails are generated. I can generate the thumbnails manually however. Let me know if getting a more simplified hip file together would help, or if this is a known issue.

As a quick fix, I forced the "has_geo_variants" switch to always return 0. Once I did that, I was able to save the thumbnails via TOPS. But again, this is only how I've mitigated the issue. I would love it if someone from SideFX can tell me the real fix. Thanks!

Ok, just and update here, for anyone who runs into something like this in the future. I got around this issue by making sure the checkbox that caused thumbnail generation to occur on ROP export was OFF. This turned out to be perfectly good workaround, 'cause after all the USD files were being created, I was just turning around and adding them all to a Layout Asset Gallery, which generated the thumbnails automatically. Nice!

I still don't know why I ran into this problem with that checkbox checked, but I'm off high-center without major hackery.