Unreal import of Nvidia Attic Scene

Hello,

Just stepping through some basic data sets in a number of different applications, currently investigating the Nvidia USD Attic Sample which I downloaded here: Pixar Universal Scene Description (USD) | NVIDIA Developer

Loading this USD project in Create and Unreal 4.26.1 they look quite different.

The DomeLight is not yet supported – this is expected as per the docs here: Unreal Engine 4 — Omniverse Connect documentation

However the Directional light in Unreal appears to have an incorrect intensity (much too high).

I was also curious if the Create > RTX Settings (Real-Time) > Ambient Light Intensity … has a corresponding setting in Unreal as this appears to be a large contributor to why the scene looks different in Create and Unreal.

More generally, what can we expect in terms of consistent look and feel for rendering Omniverse content in Unreal? Which settings should we typically enable / disable to achieve consistency?

(I appreciate this may not be an Omniverse issue and more about understanding of Unreal in-depth.)

Looking forward to your comments!

Thanks,

Jason.

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Thanks for checking out the Attic Sample in Unreal Engine. Honestly, we were so focused on making it look amazing in Create that we never did a thorough and complete pass on it in Unreal to make it really shine.

First, we use layers in the Attic scene to do “night” lighting, to show the “day” lights you can hide the second layer. No, Unreal doesn’t show the layer names, this is because our Omniverse Layers tab needs an overhaul, but that’s not done yet :-)

Night (path traced):

Day (path traced):

DIrectional light:
We have spent a lot of time attempting to align the Directional light with the USD Distant Lights, but in UE4 we just don’t get much bounce within the room. Because of this we’re considering adding a default ambient cubemap to add some ambient lighting to the imported scenes.

I did it here by selecting the PostProcessVolume that is automatically created and assigning an Ambient Cubemap Texture from the Engine Content:

Another challenge between Create and Unreal Engine is autoexposure. I dug into this a bit in this forum post, which might shed some light things :-)

Hi Lou,

Thanks for your detailed explanation!

I’m not seeing any layers in my Unreal scene … nor any representation of day / night lighting in Create?

Just want to check we’re working with the same data set?

I downloaded mine from the link in the original post above.

Jason.

PS. Related question: is there a way to make the cubemap change stick? I’ve tried saving the current level to disk as well as saving the Attic_NVIDIA USD file (right-click ~Save to Omniverse") as well as a few different ways of loading the Omniverse scene, but the change doesn’t persist.

Jason, the download site you mention is just an older version of the Attic stage with only a single layer. We plan to provide a method to download the latest version soon. In the mean time, you can get the latest, multilayer version from the /NVIDIA mount when you install the collaboration service (localhost Nucleus server).

There is no way to currently get the cubemap change to stick in USD. I think once we incorporate some sort of import mechanism to generate a possible Ambient Cubemap Texture and maybe even a skylight (for the domelight texture) there will also be an export that will save the setting to the stage.