Even if you constrain by contracting the bounding box by 1D?
DLM
"Trevor G Quayle" <Tin### [at] hotmailcom> wrote in message
news:web.446a1f9ef5b1f07d6c4803960@news.povray.org...
> Interestingly if you constrain the entire sphere volume to the given area> (20x20) rather than the center positions, the parse time triples...>> -tgq>>