Gerald K. Dobiasovsky wrote in message <382b9791@news.povray.org>...
>The basic algorithm doesn't seem to have changed since DKB,
>but since POV 3.0 the random float table exists precomputed in
>"texture.c" rather than being calculated from a CRC table after startup.
>(The range of the numbers in the table is -1.0 < # < 1.0)
>
>I am surprised your results are shifted towards negative values.
>Looking at the algorithm used
>(at least as I understand it, or, rather, I believe I understand it :) )
>one would expect its range to be bigger than -0.5 to 0.5,
>but still with a symmetrical distribution about 0.0!


The problem here is with the specific precomputed table.  A different table
would give a different set of values, and it is possible to design a table
that gives the correct behavior.

Mark

Post a reply to this message