POV-Ray : Newsgroups : povray.general : Isosurface question Server Time
3 Aug 2024 02:16:31 EDT (-0400)
  Isosurface question (Message 1 to 4 of 4)  
From: Timothy Cook
Subject: Isosurface question
Date: 23 Jun 2004 12:32:46
Message: <40d9b0ae$1@news.povray.org>
I have an scene as follows,

#include "functions.inc"
#declare fn_Image=function{
   pigment{
     image_map{
       tga "C:\Data\3D\POV\isotest01.tga"
       map_type 1
       once
     }
   }
}
isosurface{
   function{f_sphere(x, y, z, 1)-fn_Image(x, y, z).gray}
   contained_by{sphere{0,2.01}}
   accuracy 0.001
   max_gradient 100
   pigment{color rgb 1}
}

This behaves in the follwing manner:  a sphere with radius 1 has
extrusions based on the grey value of a pixel, with 255 extending
1 unit from the surface of the sphere.  If I change the equation to

   function{f_sphere(x, y, z, 1)+fn_Image(x, y, z).gray}

(to make the grey values indentations) or reduce the radius of the
sphere, i.e.

   function{f_sphere(x, y, z, 0.5)-fn_Image(x, y, z).gray}

(to decrease the size of the surface failing making indentations) all
that results is a sphere with radius 1 and no surface distortions.

How might I make working versions of formulas 2 and 3, or am I
restricted to extruding from a base sphere of radius 1 or larger?

-- 
Tim Cook
http://home.bellsouth.net/p/PWP-empyrean

-----BEGIN GEEK CODE BLOCK-----
Version: 3.12
GFA dpu- s: a?-- C++(++++) U P? L E--- W++(+++)>$
N++ o? K- w(+) O? M-(--) V? PS+(+++) PE(--) Y(--)
PGP-(--) t* 5++>+++++ X+ R* tv+ b++(+++) DI
D++(---) G(++) e*>++ h+ !r--- !y--
------END GEEK CODE BLOCK------


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From: Mike Williams
Subject: Re: Isosurface question
Date: 23 Jun 2004 14:07:44
Message: <nqyl0GAvac2AFwNL@econym.demon.co.uk>
Wasn't it Timothy Cook who wrote:
>I have an scene as follows,
>
>#include "functions.inc"
>#declare fn_Image=function{
>   pigment{
>     image_map{
>       tga "C:\Data\3D\POV\isotest01.tga"
>       map_type 1
>       once
>     }
>   }
>}
>isosurface{
>   function{f_sphere(x, y, z, 1)-fn_Image(x, y, z).gray}
>   contained_by{sphere{0,2.01}}
>   accuracy 0.001
>   max_gradient 100
>   pigment{color rgb 1}
>}
>
>This behaves in the follwing manner:  a sphere with radius 1 has
>extrusions based on the grey value of a pixel, with 255 extending
>1 unit from the surface of the sphere.  If I change the equation to
>
>   function{f_sphere(x, y, z, 1)+fn_Image(x, y, z).gray}
>
>(to make the grey values indentations) or reduce the radius of the
>sphere, i.e.
>
>   function{f_sphere(x, y, z, 0.5)-fn_Image(x, y, z).gray}
>
>(to decrease the size of the surface failing making indentations) all
>that results is a sphere with radius 1 and no surface distortions.
>
>How might I make working versions of formulas 2 and 3, or am I
>restricted to extruding from a base sphere of radius 1 or larger?
>


I can't reproduce your problem in either 3.5 or 3.6. Are you absolutely
sure that you didn't change anything else, like the size of the
"contained_by" sphere?

-- 
Mike Williams
Gentleman of Leisure


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From: Timothy Cook
Subject: Re: Isosurface question
Date: 23 Jun 2004 20:26:00
Message: <40da1f98@news.povray.org>
Mike Williams wrote:
> I can't reproduce your problem in either 3.5 or 3.6. Are you absolutely
> sure that you didn't change anything else, like the size of the
> "contained_by" sphere?

*checks scene*

Oh FRELL me!  I had a sphere r=1 that I still had flagged to export
in Moray!

*bangs head on wall*

X.x;

Erm...thanks for assising me in overcoming my 
early-morning-before-going-to-sleep stupidity ^_^

-- 
Tim Cook
http://home.bellsouth.net/p/PWP-empyrean

-----BEGIN GEEK CODE BLOCK-----
Version: 3.12
GFA dpu- s: a?-- C++(++++) U P? L E--- W++(+++)>$
N++ o? K- w(+) O? M-(--) V? PS+(+++) PE(--) Y(--)
PGP-(--) t* 5++>+++++ X+ R* tv+ b++(+++) DI
D++(---) G(++) e*>++ h+ !r--- !y--
------END GEEK CODE BLOCK------


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From: Thomas de Groot
Subject: Re: Isosurface question
Date: 24 Jun 2004 03:10:51
Message: <40da7e7b$1@news.povray.org>
"Timothy Cook" <z99### [at] bellsouthnet> schreef in bericht
news:40da1f98@news.povray.org...
> Oh FRELL me!  I had a sphere r=1 that I still had flagged to export
> in Moray!
>
Frell? Is there a Luxan aboard?

Thomas


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