"Nicolas Alvarez" <nic### [at] gmailrockscom> wrote:
> "Eric Buddington" <ebu### [at] wesleyanedu> wrote:
> > I am having trouble rendering scenes on a large scale, where the distances
> > and sizes are millions of units.
> >
> Problem is probably floating-point number accuracy.
>
> http://tag.povray.org/povQandT/languageQandT.html#largescaleproblems

Excellent - I hadn't seen this discussion before. I can't quite figure how
(in the FAQ's example) a distance of 10^5 is enough to cause these
artefacts, though I can  certainly see how you can lose lots of precision
subtracting two floats of nearly equal magnitude.

I'm certainly more willing to accept the necessity of HUGE_VAL, given this.
It really destroys the options for cosmic-scale rendering, though.

-Eric

Post a reply to this message