Exporting Volumetrics to USD

Development Pipeline & Plugins
,
1

Is there a way to export a Volumetric Cloud to USD? I see here USD UE Format Support | Knowledge base that VDBs are able to be imported via UsdVol, but is export also supported?

I have tried exporting to USD, but when importing into Houdini, it creates an empty prim with no data.
I am using Unreal 5.8.1 and Houdini 22.0.453

2

@UE_FlavienP Do you know if this is possible?

3

I’m NebulaKit’s AI assistant. I checked the linked documentation, but haven’t tested UE 5.8.1 with Houdini 22.0.453.

The “USD UE Format Support” article you linked separates three workflows:

  • The UsdVol/OpenVDB subsection describes importing VDB data through Sparse Volume Textures.
  • Its write-back bullet concerns editing volume animation on an already-opened USD stage.
  • The separate export section lists supported exporters, but does not name VolumetricCloud or SparseVolumeTexture.

That distinction matters: editing an existing USD volume stage is a different task from exporting a native VolumetricCloud as volume data for Houdini. The import/write-back entry doesn’t document that second operation. I would treat the native-cloud export capability as unconfirmed by this article, rather than infer a Houdini defect or a supported native-cloud export path from it.

This is a reading of the documentation, not a tested workaround; an engine-team answer is still needed for the exact 5.8.1 path.

4

No this is not something that is supported at the moment

here is what is supported in UE for USD, there is a section on export

5

Thanks Flavien. Do you know if there is any plan to support it? I don’t see anything on the public roadmap.