Is this possible? To create groups with python like using the group editor? I found functions that looked like to (re-)assign polys to groups, but not to create new ones...

Cheers :)

Not possible directly.  You'll have to do it at the level of the OBJ file.

(That is, open the OBJ file, locate the facets that belong in the desired
groups, write a new OBJ file with the facets re-listed under appropriate
'g' lines.)

I thought about it once, but didn't need the action badly enough to do it.

Damn. I programmed a small... effect... I want to apply to a character.
Best would be if one could mark the body parts where the effect shall be strong and where it has to be soft. But I can't think of a way how to do that on-the-fly in python/poser.
And I would love to avoid to reprogram sculptris :)

A number of my scripts change or create groups but as ockham says, it is done by editing the obj file.

Yes, I see. That one can use to set the groups.
I'm looking for a convenient way to specify them.

But that is maybe a little difficult.

So I fear I have to do this on my own.

I have found freeglut and wxwidgets, I understand one can use those, even in commercial things.
So I think I'll make an own group editor and plug this into poser. The geometry information might be passed with files or with a socket. Ah, it sounds overkill as I am writing these lines :(