POV-Ray : Newsgroups : povray.binaries.images : Simple Isosurface Server Time
8 Jul 2024 17:33:01 EDT (-0400)
  Simple Isosurface (Message 1 to 3 of 3)  
From: Woody
Subject: Simple Isosurface
Date: 14 Oct 2007 21:30:01
Message: <web.4712c21a4144865430d4452f0@news.povray.org>
I was testing out some of the Isosurfaces from the documentation and came
across some thing which I'm not sure if its a bug, a limitation, or so I'm
just not doing it right.

The code below renders to the attached image. There seems to be some weird
normals, shading, or with the general shape. But if I change the viewing
coordinates to something else like <3,2,5> everything looks fine.

Can anybody tell me what I'm doing wrong or make any suggestions?



#include "colors.inc"

camera {
 location <2,2,2>
 look_at <0,0,0>
}

isosurface{
        function{ abs(x)+abs(y)-1}
        contained_by {box{-1,1}}
        pigment{color White}
}


light_source {
 <2,2,2>
 color White
}


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Attachments:
Download 'isosurface.jpg' (8 KB)

Preview of image 'isosurface.jpg'
isosurface.jpg


 

From: honnza
Subject: Re: Simple Isosurface
Date: 15 Oct 2007 01:35:00
Message: <web.4712fb108375225aa9ce4df50@news.povray.org>
"Woody" <nomail@nomail> wrote:
> I was testing out some of the Isosurfaces from the documentation and came
> across some thing which I'm not sure if its a bug, a limitation, or so I'm
> just not doing it right.
>
> The code below renders to the attached image. There seems to be some weird
> normals, shading, or with the general shape. But if I change the viewing
> coordinates to something else like <3,2,5> everything looks fine.
>
> Can anybody tell me what I'm doing wrong or make any suggestions?
>
>
>
> #include "colors.inc"
>
> camera {
>  location <2,2,2>
>  look_at <0,0,0>
> }
>
> isosurface{
>         function{ abs(x)+abs(y)-1}
>         contained_by {box{-1,1}}
>         pigment{color White}
> }
>
>
> light_source {
>  <2,2,2>
>  color White
> }

Hello,
 If you look into the messages tab you may notice a message saying like
"isosurface on line 12 has its maximum gradient set to 1.1 but there was
found a gradient of 128.256. Increase the max_gradient value", very
roughly.
What happens here is that the renderer expects the function to change slower
than it actually does. That's why your surface contains holes. You can
change this expected maximum gradient value by the max_gradient keyword.


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From: Woody
Subject: Re: Simple Isosurface
Date: 15 Oct 2007 08:00:00
Message: <web.4713554c8375225a94e61a50@news.povray.org>
That did it. Thanks.


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