POV-Ray : Newsgroups : povray.binaries.images : Luna, Moon... desert satellite : Re: Luna, Moon... desert satellite Server Time
20 Oct 2021 09:13:33 EDT (-0400)
  Re: Luna, Moon... desert satellite  
From: Samuel B 
Date: 11 Sep 2021 17:20:00
Message: <web.613d1ce4756c3d5acb705ca46e741498@news.povray.org>
=?UTF-8?Q?J=c3=b6rg_=22Yadgar=22_Bleimann?= <yaz### [at] gmxde> wrote:
> Hi(gh)!



> On 10.09.21 01:40, Samuel B. wrote:
> > I should probably try the maps them out in other programs to see
> > if POV is at fault, although I doubt it is.
>
> Is there anywhere on the Web a tool to convert 16-bit PNGs to 16-bit
> (red/green) POV-Ray heightfields?

Hmm, not to my knowledge. But I have done this myself in GLSL, although I may
have gotten my math slightly wrong. It can also be done in POV-Ray using
functions and color_maps, but again the math has to be /just/ right or else you
get unintended contour lines and/or slight terraces.

> Or any other way to handle 16-bit png in POV-Ray, i. e. so that
> eval_pigment() actually reads in 65536 rather than 256 different gray
> values?

Yes, I think I can help you with. POV-Ray is the program you need. Just use a
red/green map to build a height_field like you normally would. Situate an
orthographic camera over the hf, and center the hf to fill the screen. Give the
hf a planar pigment with a reversed color_map (so that white=peaks) and an
ambient 1 finish. You may also need to specify the following command line
options: +fg and File_Gamma=1.0. This is the way I have converted red/green maps
to 16-bit pngs in the past.

> Now playing: Love Now Till Eternity (Asia)

Cool band! I think my favorite is 'Don't Cry'

Sam


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