@Peggy

Thanks a lot for the trick, it works very well, I'v been able to render the previous picture with shaders after the "Copy all to folder" operation in Poser, and also to load another PZ3 which loads only a prop with the original file.
The only drawback is that Poser stucks at the end of the process, I have to kill it, but it's not a problem.

I have a question : can I modify the new PZ3 or must I modify the original PZ3 and redo the "Copy all" operation ?

@silverblade33
Thanks for the link,  lots of content to read carefully