POV-Ray : Newsgroups : povray.programming : Suggesting trivial patch. Server Time
23 Dec 2024 02:25:09 EST (-0500)
  Suggesting trivial patch. (Message 1 to 5 of 5)  
From: Wolfgang Wieser
Subject: Suggesting trivial patch.
Date: 21 May 2003 16:45:07
Message: <3ecbe552@news.povray.org>

The images look nice but I got the following warning from POVRay: 

--------
Warning: The maximum gradient found was 0.000, but max_gradient of the
isosurface was set to 0.000. The isosurface may contain holes!
Adjust max_gradient to get a proper rendering of the isosurface.
--------

Looking at isosurf.cpp, I suggest that we replace "%f" with "%g" or 
similar. 

Wolfgang

The isosurfaces with such a little gradient can be seen here: 
http://www.cip.physik.uni-muenchen.de/~wwieser/


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From: Thorsten Froehlich
Subject: Re: Suggesting trivial patch.
Date: 22 May 2003 14:39:02
Message: <3ecd1946$1@news.povray.org>
In article <3ecbe552@news.povray.org> , Wolfgang Wieser <wwi### [at] gmxde>  
wrote:

> Looking at isosurf.cpp, I suggest that we replace "%f" with "%g" or
> similar.

Why?

    Thorsten

____________________________________________________
Thorsten Froehlich, Duisburg, Germany
e-mail: tho### [at] trfde

Visit POV-Ray on the web: http://mac.povray.org


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From: Warp
Subject: Re: Suggesting trivial patch.
Date: 22 May 2003 19:09:22
Message: <3ecd58a2@news.povray.org>
Thorsten Froehlich <tho### [at] trfde> wrote:
>> Looking at isosurf.cpp, I suggest that we replace "%f" with "%g" or
>> similar.

> Why?

  So that instead of getting "0.0000" we get something like "1.23e-6"?

-- 
plane{-x+y,-1pigment{bozo color_map{[0rgb x][1rgb x+y]}turbulence 1}}
sphere{0,2pigment{rgbt 1}interior{media{emission 1density{spherical
density_map{[0rgb 0][.5rgb<1,.5>][1rgb 1]}turbulence.9}}}scale
<1,1,3>hollow}text{ttf"timrom""Warp".1,0translate<-1,-.1,2>}//  - Warp -


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From: Thorsten Froehlich
Subject: Re: Suggesting trivial patch.
Date: 23 May 2003 09:16:07
Message: <3ece1f17@news.povray.org>
In article <3ecd58a2@news.povray.org> , Warp <war### [at] tagpovrayorg>  wrote:

>   So that instead of getting "0.0000" we get something like "1.23e-6"?

Hmm, now I see your idea behind this.  Unfortunately this won't really work
because in effectively anything below 0.0000 is pretty much below the
precision threshold you can reach with double precision floating-point
numbers for the number of calculations performed by isosurfaces.

I will see if I can come up with something intelligent to at least make the
message not show up in such case.

    Thorsten

____________________________________________________
Thorsten Froehlich, Duisburg, Germany
e-mail: tho### [at] trfde

Visit POV-Ray on the web: http://mac.povray.org


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From: Wolfgang Wieser
Subject: Re: Suggesting trivial patch.
Date: 23 May 2003 15:00:49
Message: <3ece6fe0@news.povray.org>
Thorsten Froehlich wrote:

> Hmm, now I see your idea behind this.  Unfortunately this won't really
> work because in effectively anything below 0.0000 is pretty much below the
> precision threshold you can reach with double precision floating-point
> numbers for the number of calculations performed by isosurfaces.
> 
My experience show that you actually CAN render isosurfaces with a gradient 
of less than 0.000 . 
The actual output is limited to 3 digits after the decimal point, not 4. 
Using something like %g would be appreciated. 

> I will see if I can come up with something intelligent to at least make
> the message not show up in such case.
> 
No, NOT writing the message is probably a bad idea. Because in my case 
a gradient of 0.01 already takes ages to render and I a using values 
of 0.0002 and the like. 

Wolfgang


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