Hi, I have noticed that when I use mantra, the cryptomatte data in my exr files are recognized in Fusion Studio and can be used by their cryptomatte tool. However, when including a cryptomatte pass using Karma, I get an image for cryptomatte but somehow the actual data is not present. Fusion gives an error saying that it "failed to read layer/index/channel information for layer: 'CryptoObject'" Does anyone know why the functionality is not the same between Karma and Mantra?

Hi, so we had someone internally open an EXR out of Karma, and the Cryptomatte pass displays correctly in the viewer, though the node throws a Lua error (which seems different from the one you described). So it's hard to tell if this is a bug in Fusion's Crytomatte plugin, or if it's a bug with Karma.

If you can put together a hip file showing the Karma/Mantra behaviors and log a bug, that will help us to track the issue (and better determine if there's anything we can do on our end).

I completely forgot, but this is likely because Fusion and/or Fusion's Cryptomatte plugin doesn't support the "newer" EXR format (it was introduced around 2013, I'm told).

You can append --exrmode 0to your husk command, either in the commandline or on the USD Render ROP go to the "Driver" tab and add the flag there.

Does this help?