POV-Ray : Newsgroups : povray.binaries.images : multiple image_maps as media density-- 'fake' .df3 : Re: multiple image_maps as media density-- 'fake' .df3 Server Time
2 Dec 2024 18:43:29 EST (-0500)
  Re: multiple image_maps as media density-- 'fake' .df3  
From: Kenneth
Date: 1 Nov 2024 09:10:00
Message: <web.6724ce9a7fd6ccd91c33a706e066e29@news.povray.org>
"Kenneth" <kdw### [at] gmailcom> wrote:
> yesbird <sya### [at] gmailcom> wrote:
> >
> > 2. How it will work for isosurface approach?
>
> I am working on that at the moment (thanks for the suggestion!) I will post the
> result when finished.
>

Here is the isosurface example, using the same series of images. It worked,
although I had difficulty with the noise in the original images.

The PIG_SLICES function code is the same as before, but instead of using it for
media, I used...

isosurface {
  function {1.19 - PIG_SLICES(x,y,z).red}
  contained_by {box {.001, .999}}
  threshold .65
  accuracy .0001
  max_gradient 390

texture{...}
}


I chose the various values-- especially the 1.19-- to try and eliminate as much
of the noise as possible...without wiping out *too* much of the detail. Then I
rotated the isosurface into a more visually interesting orientation.

Surprisingly, it does not show a 'stair-step' appearance from the individual
image_maps; they are all nicely blended together.

Thanks yesbird for the inspiration! While working on this, I discovered
something important (and off-topic) that has given me big problems in the past,
concerning the fact that this isosurface actually responds to *lighting*. I was
not expecting that. The reason why is worth a separate post, if I can get around
to it. ;-)


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