Thank you for that information. I did play with the antialiasing setting, but except for a tremendous increase in rendering time I did not achieve any positive effect. The dots were still there.
http://sdrv.ms/14Wl3IS . obviously it would be great to get this solved.

On another rendering issue: I ...

here is an example for mode 4 rendering
http://sdrv.ms/Y19qfI

here is the link to the mode 3 rendering of the same view.
http://sdrv.ms/14LYR36

-bernd

I am building two private homes for myself and thus find sweethome3d just perfect to visualize the homes upfront.

I need to say that I do suffer from exactly the same black pixel problems as Christian has in rendering mode 4 . Especially for simulating time of day sunlight and night artificial ...