POV-Ray : Newsgroups : povray.general : height_field smooth Server Time
15 Nov 2024 03:21:34 EST (-0500)
  height_field smooth (Message 1 to 7 of 7)  
From: Rafal 'Raf256' Maj
Subject: height_field smooth
Date: 11 Dec 2004 00:09:53
Message: <Xns95BC3EEAD2C01raf256com@203.29.75.35>
I have problem with sommthi height fields - they have random black 
spots/parts. Problem is connected with smooth (without it it works ok), 
with light/shading (because using diffuse 0 ambient 1 helps).

Example:

#if (1)
  height_field {
    png "../media/bmp/hf/gory2.png"
    smooth
    translate <-.5, -40/256 ,-.5>
    scale <70000,10000,70000>
    texture { texLand1Far3 }
  }
#end  
      
#if (1)      
  height_field {  
    tga "../media/bmp/hf/gory3b.tga"
    smooth
    translate <-.5, -40/256 ,-.5>
    scale <70000*5,1,70000*5>    
    texture { texLand1Far4 }
    scale <1,80000,1>
  }
#end

I think that such problem was disscused here before, wasn't the path 
applyed to MegaPov 1.1 nor PovRay 3.6.1 (tested in both, on Win32)?





-- 
http://www.raf256.com/3d/
Rafal Maj 'Raf256', home page - http://www.raf256.com/me/
Computer Graphics


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From: Tim Nikias
Subject: Re: height_field smooth
Date: 11 Dec 2004 02:14:39
Message: <41ba9e5f$1@news.povray.org>
This is a known problem. The "smooth" keyword, especially when resizing the
height_field, may result in unexpected shadow artifacts. One possibility is
to use double_illuminate and/or no_shadow, another is to use an isosurface
or just write a script to calculate the mesh yourself.

IIRC correctly, the problem is due to the calculated normal's and how they
are moved about and scaled when resizing the heightfield, but someone with
more expertise might know the actual, 'correct' bug. ;-)

Regards,
Tim

-- 
"Tim Nikias v2.0"
Homepage: <http://www.nolights.de>


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From: Christoph Hormann
Subject: Re: height_field smooth
Date: 11 Dec 2004 04:10:01
Message: <cpedev$1vp$1@chho.imagico.de>
Tim Nikias wrote:
> 
> IIRC correctly, the problem is due to the calculated normal's and how they
> are moved about and scaled when resizing the heightfield, but someone with
> more expertise might know the actual, 'correct' bug. ;-)

No, such a bug existed but has been fixed in 3.6 IIRC.  AFAIK there are 
no known bugs related to heightfields that are not fixed.  Of course 
smooth heightfields suffer from the same problems as smooth meshes.

Christoph

-- 
POV-Ray tutorials, include files, Sim-POV,
HCR-Edit and more: http://www.tu-bs.de/~y0013390/
Last updated 23 Sep. 2004 _____./\/^>_*_<^\/\.______


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From: Warp
Subject: Re: height_field smooth
Date: 11 Dec 2004 10:33:04
Message: <41bb1330@news.povray.org>
Christoph Hormann <chr### [at] gmxde> wrote:
> Of course 
> smooth heightfields suffer from the same problems as smooth meshes.

  And as for those, see sections 2.4.8 and 2.4.9 of the documentation.

-- 
#macro N(D)#if(D>99)cylinder{M()#local D=div(D,104);M().5,2pigment{rgb M()}}
N(D)#end#end#macro M()<mod(D,13)-6mod(div(D,13)8)-3,10>#end blob{
N(11117333955)N(4254934330)N(3900569407)N(7382340)N(3358)N(970)}//  - Warp -


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From: Jacquier Marc
Subject: Re: height_field smooth
Date: 11 Dec 2004 11:47:59
Message: <41bb24bf$1@news.povray.org>

news:41bb1330@news.povray.org...
> Christoph Hormann <chr### [at] gmxde> wrote:
> > Of course
> > smooth heightfields suffer from the same problems as smooth meshes.
>
>   And as for those, see sections 2.4.8 and 2.4.9 of the documentation.
>
don't you mean 9.9.1 to 9.9.3?

Marc


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From: Warp
Subject: Re: height_field smooth
Date: 11 Dec 2004 17:28:57
Message: <41bb74a9@news.povray.org>
Jacquier Marc <jac### [at] wanadoofr> wrote:
> don't you mean 9.9.1 to 9.9.3?

  There are only three chapters in the current POV-Ray documentation.

-- 
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: Marc Jacquier
Subject: Re: height_field smooth
Date: 12 Dec 2004 07:56:52
Message: <41bc4014$1@news.povray.org>

news:41bb74a9@news.povray.org...
> Jacquier Marc <jac### [at] wanadoofr> wrote:
> > don't you mean 9.9.1 to 9.9.3?
>
>   There are only three chapters in the current POV-Ray documentation.
>
> -- 
Sorry, I was talking about POV-Ray 3.5 doc :/

Marc


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