We're making heavy use of aiSetParameter nodes in our look dev and lighting pipeline - we basically use them to assign materials, smooth geometries, apply displacement, etc.. etc.
While working on a very big maya scene with many assets and aiSetParameter nodes we noticed that the scene was very very slow to render, even though it was not so complex.. I mean we've done way more than that. :)
We currently use mtoa 184.108.40.206, and we decided to check the release notes of version 220.127.116.11 which, among the other things, say:
Fixed slowdown with many operators
So we downloaded the new version in order to test if the slowdowns were fixed (we tried both 3.2.2 and 18.104.22.168 to be honest).
But we discovered that some aiSetParameter nodes (created with the 22.214.171.124) are not working anymore with 3.2.2 - they give the classic pinkish color at render time, as if they were not evaluating correctly. Of course all of the nodes were working exactly fine in the previous version.
We also noticed that in this version (3.2.2) we have to check Export all shading groups in the arnold render settings in order to make the aiSetParameter work.
Now, if we create new aiSetParameter nodes and use them to assign shaders they work just fine, so it appears that it's just that the old ones for some reason are not compatible with this arnold version.
Can you confirm it? We've got quite a few assets already done with the old version, it seems odd that we should republish them just because of this regression between minor versions.
Maya version is 2018.6, OS is Centos 7.6.
Steps to reproduce the issue
Create an aiSetParameter node in version 126.96.36.199, upgrade mtoa to 3.2.2 and check that it works.