This question is similar to this [www.sidefx.com] post but the differences appear in render and not just viewport, so I figured it's different enough of a problem.
Any ideas of where to look to debug why this is different pre and post exporting as a USD?
Turn on the Renderman Ris setting in the Viewport (in Solaris)
Click "Save to Disk" on the usdrop node
See the differences in the sparks' intensity between the material assignment node and the reference node that pulls in the USD that was saved out by the usdrop
Thanks, I can reproduce this. It's not immediately obvious to me if this is a Solaris or USD or RenderMan thing, but I'm going to have a closer look early next week.
robp_sidefx Thanks, I can reproduce this. It's not immediately obvious to me if this is a Solaris or USD or RenderMan thing, but I'm going to have a closer look early next week.
Awesome! Yeah, I'm very interested in what's going on.
Okay, I had another look and I think it's a RenderMan thing, where it's trying to interpolate primvars for the curves geometry that has changing topology. If I export a USD file and try to load it into usdview I get errors along the lines of "primvar 'widths' size (2) did not match expected (4)". I don't see the same thing happening with Karma.
I'd suggest chatting with Pixar as a next step and seeing if they have any advice.
robp_sidefx Okay, I had another look and I think it's a RenderMan thing, where it's trying to interpolate primvars for the curves geometry that has changing topology. If I export a USD file and try to load it into usdview I get errors along the lines of "primvar 'widths' size (2) did not match expected (4)". I don't see the same thing happening with Karma.
Okay, cool! I'll put something on the Renderman Discord. Also, I'm not able to reproduce the errors about the widths primvar.
