Margus Ramst wrote:
> 
> Before I post a bug report, I'd like some confirmation of what I've found. There
> seems to be a (very conspicuous) bug in the various noise functions. It exhibits
> itself as banding after a certain _negative_ distance

You are likely seeing roundoff errors.  The basic solid noise function
is only good down to around -10000.  After an octave or two (chop in
half each time), this number gets pretty small.  Could be the reason you
are seeing it at -80 or so.

To test this theory, you can change the definition of MINX (in
texture.c) to something along the lines of -10000000 (plenty of digits
in a double to handle six or seven digits in the integer part and a
whole bunch below).

I've seen this sort of thing before.  In that particular instance, the
coordinates of the thing I was rendering were very small (like -100000),
with the camera down there also.  Turned bumps into a really odd checker
sort of thing.  Changing coordinates did the trick.

Xander

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