You can create a skp file with all the custom materials you use, render the scene, then you export the skp file to .ocs. So you have a "catalog of samples file" of your custom materials.
After that you can import the materials from .ocs file using the material editor. You can also choose what ...

you can always use standalone version ha ha ha

thank you rfox,
It worked well!
To avoid the loss of IES data from the file I've found this method useful:
create a diffuse/emission/emission texture/graysacle image/file.ies material and press "Apply" button (as you said).
save the file, close all the octane viewports, save the file again and close ...

ok,
thank you

thank you perro_abombao for the reply,
I've tried the various settings and it seems to work,
a problem occurs when I save the file, close sketchup and re open the file: the renderer doesn't show the IES emission of the light source, as the material editor continues to show the parameters saved ...

thank you for the useful answer

thank you for the useless answer

I use octane in sketchup (not in standalone version), and this is a Octane for sketchup forum.
In the video the rollouts and command are different.

thank you

How can I add IES light?
thanks
mac
(...and eliminate white pixels in metal material reflections in a interior render with lights?)

thank you smicha,
I've tried to use Ol' Ready Cam (ORC)and it works well,
the matter is that I'n not very interested in using standalone version, I'm a sketchup user and I'd like to
stay in the skp environment.

mac