Found a simple solution not involving updating to MacOS Monterey: Just set the USE_OPENGL to 0 (was 1) and everything is fine. 

just found it on anther site - thanks anyway.

@EldritchCellar: Seems RSRconv for mac is no longer available. Do you have a copy and would you mind to share it?

Bingo! Thank you both very much and a special thank you to svdl for the clear description how to resolve the issue.

My page file was 2047 MB, obviously too small. Checked with Vue d'Esprit too and found that Vue uses 100% of the processor capacity while rendering. Poser 6 obviously doesn't support hyperthreading.

If you ever are in Basel, Swiitzerland send me an email, I owe you a beer or two ...

Regards,
Christoph

And there is a 30-day trial version!

Thanks, Christoph

Thank you both.  If NURBS in fact are splines I think I'll try MoI. This program seems to have a clean user interface and is consideably cheaper than Rhino.

Regards, Christoph

There is a free plant generator here http://ngplant.sourceforge.net/

Regards, Christoph

If you have Poser there is a nice spanish moss model at RDNA!
Christoph

My memory didn't work correctly as usual. For those interested here is the correct name of the Photoshop brush set I had in mind:

Product: Water Droplet Kit for Photoshop
Creator Name: Arie L. Stavchansky (LazloHollyfeld on Renderosity)
Email:   lazlohollyfeld@sbcglobal.net
Copyright: 2004 by Arie L. Stavchansky

Unfortunately I can't tell you if it's still available.

Christoph

I have once seen a package for Photoshop in the Renderosity store called "drop maker" or something similar. With this you could paint drops of water over any texture.

Regards, Christop

I think you can bring down the grainyness to an acceptable level with appropriate render settings. The "superior" setting is not good enough and the "ultra" setting is too slow. Here is what I use:

• Antialias "fine"; min. 9, max. 12 pixel oversampling; quality level 70%
• secondary effect quality level 65 %
• render your scene bigger than needed, I use 1600 x 1200 in most cases. Than reduce size
    in Photoshop. If you like you can sharpen the image once, this makes it more crisp.

These settings do the job for my taste in most cases, see my gallery for examples if you like. 

Of course the price is rendering time. So thanks for the "Neat Image" hint, I'll give it a try.

Best regards, 
Christoph

I had the same problem with Vue 5 Esprit. If you have Vue 5.10 you will have to go back to version 5.09. E-on says they have fixed this with version 5.11, however I have not tried this upgrade because it is still beta. 5.09 works fin for me.

Best regards, Christoph

It was just a delay, got all messages this morning! Sorry for disturbing but I never observed any delay up to now! Thanks for your help and best regards, Christoph

I don't have a modelling application, so I can't try untriangulating and polygons. Vue can invert surface normals of meshes however. I tried this and then all parts of the mesh became invisible (not black), there was nothing left. I think this is an indication, that all surface normals point in the right direction, i.e. to the outside of the mesh. I'm not absolutely sure about this however.

You are right, it's a Hankster rock formation. I had similar artifacts with other meshes too, but this one is the worst by far up to now. I like the models a lot just the same ...