A Favor to Ask Since I Have Not Compiled usdcat

I am trying to write an exporter to Blender that includes armatures, but I cannot find much documentation on the Blender side. I’ve found an example that Blender successfully imports, but it is usdz and so I cannot inspect it, nor do I have usdcat.

May I impose on some gentle soul to download


and then convert it to usda with usdcat and make it available to me somehow so I can reverse engineer importing bones is Blender/USD?

It’s be greatly appreciated.

Hi there,

There’s already full support for armatures with shape keys in the universal-scene-description branch:

This is the same build we at NVIDIA distribute through the Omniverse launcher. Before writing your own solution, kindly try ours.

All the source code is in the open, under the universal-scene-description branch name. We are hoping to have this feature in main for 4.1, but can’t promise timing.

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Also - if all you want to do is inspect a .usdz, you may not need usdcat - it’s just a .zip file (with certain structure + requirements), so you can just change the extension to .zip and open it with any archive manager to extract the files.

Of course, if what it contains is a .usdc, then you may still need usdcat.

In that case, if you’re on Windows or Linux, you can download the pre-built USD NVIDIA binaries from here.

These also include wrapper scripts which do all the necessary environment var setup, so all you need to do is open a shell, and do:


<EXTRACTED_USD>\scripts\usdcat -o your_usd.usda your_usd.usdc 


<EXTRACTED_USD>/scripts/usdcat.sh -o your_usd.usda your_usd.usdc 

Hi Charles, thank you for this insight. I also need to figure out vertex groups, or maybe with how USD supports deformations, they’re not strictly necessary. I’ve got a starting point, now.

Thanks again,

Hi Paul,

The example was, in fact, a compressed usdc, not what I wanted. But the binary usdcat worked perfectly, so that you very much for that link, which I had not known about. Building on Ubuntu was becoming a royal pain satisfying the dependencies. It didn’t occur to me to check the NVidia site for binaries, and more interestingly your link did not come up when I googled for USD binaries.

Thanks again,

I wonder if you got hit by the boost download problem at jfrog that occurred over the last few days? Satisfying the dependencies shouldn’t be a pain if the various archives are available, so please feel free to start a new topic if you’d like to investigate.

Hi Nick,

Thanks for your reply. It was rather just the sheer number of packages that cmake would require, and the iterative nature of it. I think that had I persevered, it eventually would have built.


Oh, it sounds like you were trying to build straight from cmake rather than the build script which does all the downloading for you. That’s quite challenging if you want some of the extras like openimageio and haven’t got it sitting around already.