> What you're seeing is a long-standing problem known as "[near]
> coincident surfaces": If POV-Ray encounters one transparent or
> semi-transparent surface, the ray traced from there onward will ignore
> any surface within a particular distance.
>
> The rationale for this behaviour is that the ray can't erroneously
> re-encounter the transparent surface (or any surface truly coinciding
> with it) again, which could happen due to rounding errors, and might
> lead to a potentially infinite loop.
>
> As a consequence, you need to make sure that you leave a bit of a gap
> between any transparent or semi-transparent objects and adjacent objects.
>
> Since the required minimum distance is a constant, scaling up the entire
> scene allows you to get away with a smaller /relative/ distance.

Thank you very much for the quick help. Your explanation is most helpful and
comprehensible. And scaling everything up seems like a very reasonable solution.

I am sorry for having posted a recurring problem, my initial search didn't yield
any results.

Post a reply to this message