Universal Scene Description (USD) exporter feedback

Blender can now export USD files (commit ec62413f803ee506). This is still an experimental feature, as the structure of exported USD files is subject to change. You can enable the USD exporter in the Experimental Features preference. The ‘Give Feedback’ button that you find there leads to this topic.

Goal of this topic

The goal of this topic is to get feedback on the features as they are currently implemented in the master branch. It is not for more feature requests. If you find issues with the implementation, or know of ways to improve the current functionality, please write below.


Hello Sybren,

thanks for your hard work on the blender usd-exporter!
I tested the export in Blender and imported the usd-files in Clarisse iFX.
The geometry import seems fine, the only problem I ran into is, that shading groups don´t get exported or clarisse can´t read them.
In Clarisse all objects have the same default shading group.
If I export an object from blender as alembic, clarisse ifx can read also the shading groups.
If you need screenshots or files let me know.
I hope you can fix it easiely?! That would be great because USDs load >10 times faster in Clarisse iFX then alembic files.

The shading group is the name of the material that is associated with a geometry.
There is a checkbox in the usd-exporter to export materials.
Is there a way to test that the materials got exported with the accosiated geometries? I searched for a usd viewer. The only one I found was the pixar usdview but you need to have some coding skills to use it. I think you tested while writing the usd-exporter, that the materials get exported too.
Maybe its the fault of the program Clarisse iFX i use?

A low-level way that’ll work without any special tools is to save to a USDA file. Just use somefile.usda as export filename, and it’ll save it to a text-based representation. You can then open that in any text editor and read it.

I indeed used Pixar’s USDView, but that doesn’t support multiple materials per mesh either. I used the above method to check :wink:

Could very well be.

Hi Sybren, I downloaded your temp USD for Mac, enabled the experimental USD feature, but not seeing any USD import or export option.

Just test it exporting from blender to unity. Geometry exchange works as expected but no materials or textures are transfered, this is probably an actual limitation right now, but will it be possible in the future? or is just what it is?

The branch you saw was for testing something USD-related for macOS, but does not have USD support itself. The USD library still has to be built for macOS (you can see that there is no ‘usd’ directory in Subversion), and as such that build doesn’t have USD support yet. It shouldn’t be shown in the experimental features at all; this is a bug I’ll look into tomorrow.

Only viewport materials are exported, not the materials themselves. You can find more about this in the wiki.