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! 