USD-encoded MaterialX ? (updated for UE5.6)

Work on node group support did not start. One day it will end up in main but I have not ETA.

This is a bit of a stop-start exercise unfortunately. I see that MDL shaders are included with the Omniverse Kit application, which explains why the USDs render correctly there. However, they are not included in the zip files the client sends out, which seems to explain why they do not render correctly in Unreal. With apologies for imprecise language, can these be imported into Unreal? It would seem like a silly question except for the fact Nvidia have apparently incorporated MDL into the OpenUSD format. In an ideal world solutions would not be more complicated than ctrl-c - ctrl-v! :rofl: