I think I understood that one of the things that I criticize about Solaris is the time that the USD rop takes, with the use of the HUSK to do simple rendering (negligible time when it comes to launching an animation), while rendering in the viewport is very fast.
To overcome this problem, when I render a still image, I go through "render gallery" where I launch a background render.
This goes as fast as via the viewport, and therefore much faster than using USD rop.
The rendered image is automatically saved in the "galleries" folder, in exr which I can open afterwards in my compositing software.
The problem is that the cryptomatte doesn't work. In the Gallery render it displays well, but is unusable in software (like nuke for example...).
Am I missing something?
Here you can fin a screenshot and the houdini file :