Hello, I'm looking for help.

I'm trying to export a USD with ROP USD from solaris and import it in Unreal ( geo, lights, MtlX) I have enabled the USD plugin in Unreal, but I'am having issue with the shaders.

I tried 2 different methods:
- Importing with stage actor ( no shader are imported )
- Importing with a drag and drop, but the diffuse map in not interprated as sRGB ( unreal setup as linear)

I have searched for solutions on Google, Discord, and the SideFX forum, but I haven’t found a clear answer.

Thanks for your advices.

Have you switched the render context to Mtlx in the USD Stage Options menu?




Some more answers here:
https://forums.unrealengine.com/t/usd-encoded-materialx-updated-for-ue5-6/2378503/7 [forums.unrealengine.com]
https://forums.unrealengine.com/t/usd-and-materialx/1337085/12 [forums.unrealengine.com]
https://forums.unrealengine.com/t/solaris-and-materialx-support-in-5-3/1265702/6 [forums.unrealengine.com]

I ran into something similar when testing USD workflows between Houdini and Unreal. From what I've seen, MaterialX support in Unreal is still fairly limited, so geometry usually transfers more reliably than shader networks.

For the texture color issue, it's worth checking the imported texture assets individually. Unreal sometimes imports base color textures as linear instead of sRGB, especially through USD, so enabling the sRGB flag on albedo/base color maps often fixes the washed-out look.

If you need a production-ready pipeline today, many teams still export geometry via USD but recreate or assign materials in Unreal using Material Instances rather than relying on automatic MaterialX translation. It's a bit more work initially, but it tends to be much more predictable.

Out of curiosity, which versions of Houdini and Unreal are you using? The USD importer has changed quite a bit between Unreal releases, so that information might help narrow down the issue.