POV-Ray : Newsgroups : povray.beta-test : v3.8b2. height_field input values at 0.0 not clean. Server Time
21 Dec 2024 12:54:02 EST (-0500)
  v3.8b2. height_field input values at 0.0 not clean. (Message 21 to 21 of 21)  
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From: Kenneth
Subject: Re: v3.8b2. height_field input values at 0.0 not clean.
Date: 19 Feb 2023 11:35:00
Message: <web.63f24f1d1428d28b9b4924336e066e29@news.povray.org>
"Bald Eagle" <cre### [at] netscapenet> wrote:
> William F Pokorny <ano### [at] anonymousorg> wrote:
>
> > In looking at your results I'm not at all sure why the max extent values
> > for x and z are all zero? The HF max extent should be 1 or larger for x
> > and z (always I think if not scaled) ?
>
> This got me curious as well.
>
> So I just threw some quick lines of code together.
>
> The hf looks fine to me.   Typo in Ken's code?
>

Oooh, yet another one! You're absolutely right, I screwed up my #debug
statements, a cut-and-paste error from running  so many tests. I never actually
used my max_extent values. :-[  So sorry. That was a real whopper of a mistake.
My apologies to William P for 'chasing this down a rabbit hole'.

Using my now-corrected code, these are today's results:
function 500,500 {0}

MIN_EXT = <0.0000000000, -0.0000000153, 0.0000000000>

MAX_EXT = <1.0000000000, 0.0000000153, 1.0000000000>

--- BTW: For a somewhat quicker test, the HF could use   function 2,2 {0}
instead; the resulting planar HF still looks fine as an object, and also
produces the speckles vs. no-speckles comparison.


> 1/pow (2, 16) = 0.00001526

That's fascinating; I didn't realize that my 'jump' point had a computational
basis. Thanks!


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