POV-Ray : Newsgroups : povray.general : Heightfield Type problems. Server Time
17 Nov 2024 13:18:41 EST (-0500)
  Heightfield Type problems. (Message 1 to 9 of 9)  
From: S McAvoy
Subject: Heightfield Type problems.
Date: 17 Mar 2003 06:33:06
Message: <3e75b23b.246070110@news.povray.org>
1.	I created a ppm file in PovRay to use as a heightfield. When I used it
in a test scene I got this error.

 File: C:\Graphics\Moray For Windows Beta\PovScn\type02.pov  Line: 86
  height_field {

    ppm  "C:\data\images\type010.ppm" <----ERROR

Parse Error: Unsupported number of colors (0) in PPM image.

Returned from renderer with error status

It seems strange that there is a problem reading from a file that PovRay
generated itself. 

2.	Another problem is with the pgm format. If the file (in ASCII) has a
comment character "#" I get this error.

Parse Error: Invalid width or height read from PPM image.

If I use ASCII format I can edit out the comment lines so it's no bid deal but
it would be nice not to. 


Regards
        Stephen


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From: Christoph Hormann
Subject: Re: Heightfield Type problems.
Date: 17 Mar 2003 07:46:33
Message: <3E75C3A8.411EA06E@gmx.de>
Yes, there are a lot of things broken about ppm/pgm support in 3.5.  Until
now i found:

- comments are not allowed *before* the width and height values in either
pgm or ppm.  
- ppm reading support strongly broken (problems with the 'depth' value)
- continued trace of ppm does not work
- 16 bit binary pgm not supported although allowed in pgm specs (this has
never been supported though)

Parts of it have already been reported in:

Subject: ppm bug
Date: 28 Dec 2002 10:16:11 -0500
From: ingo <ing### [at] tagpovrayorg>
Reply-To: ing### [at] tagpovrayorg
To: bug### [at] povrayorg
Newsgroups: povray.bugreports

Christoph

-- 
POV-Ray tutorials, include files, Sim-POV,
HCR-Edit and more: http://www.tu-bs.de/~y0013390/
Last updated 28 Feb. 2003 _____./\/^>_*_<^\/\.______


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From: Warp
Subject: Re: Heightfield Type problems.
Date: 17 Mar 2003 07:52:09
Message: <3e75c4f9@news.povray.org>
Christoph Hormann <chr### [at] gmxde> wrote:
> Yes, there are a lot of things broken about ppm/pgm support in 3.5.

  A temporal work-around would be to simply convert the ppm file to
another format supported by POV-Ray (eg. png).

-- 
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: Tom Melly
Subject: Re: Heightfield Type problems.
Date: 17 Mar 2003 08:06:07
Message: <3e75c83f$1@news.povray.org>
"Warp" <war### [at] tagpovrayorg> wrote in message news:3e75c4f9@news.povray.org...

>   A temporal work-around would be to simply convert the ppm file to
> another format supported by POV-Ray (eg. png).

Looks more like a temporary work-around to me. A temporal work-around would
presumably involve a time-machine and a copy of 3.52 ;)


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From: S McAvoy
Subject: Re: Heightfield Type problems.
Date: 17 Mar 2003 08:27:46
Message: <3e75cca0.252827416@news.povray.org>
On Mon, 17 Mar 2003 13:46:32 +0100, Christoph Hormann <chr### [at] gmxde>
wrote:

>
>
>Yes, there are a lot of things broken about ppm/pgm support in 3.5.  Until
>now i found:
>
>- comments are not allowed *before* the width and height values in either
>pgm or ppm.  
>- ppm reading support strongly broken (problems with the 'depth' value)
>- continued trace of ppm does not work
>- 16 bit binary pgm not supported although allowed in pgm specs (this has
>never been supported though)
>
>Parts of it have already been reported in:
>
>Subject: ppm bug
>Date: 28 Dec 2002 10:16:11 -0500
>From: ingo <ing### [at] tagpovrayorg>
>Reply-To: ing### [at] tagpovrayorg
>To: bug### [at] povrayorg
>Newsgroups: povray.bugreports
>
>Christoph

Thanks for the reply, I should have checked before posting. As iit has been
reported NFAR 
>
>-- 
>POV-Ray tutorials, include files, Sim-POV,
>HCR-Edit and more: http://www.tu-bs.de/~y0013390/
>Last updated 28 Feb. 2003 _____./\/^>_*_<^\/\.______

Regards
        Stephen


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From: S McAvoy
Subject: Re: Heightfield Type problems.
Date: 17 Mar 2003 08:28:45
Message: <3e75cd56.253009328@news.povray.org>
On 17 Mar 2003 07:52:09 -0500, Warp <war### [at] tagpovrayorg> wrote:


>  A temporal work-around would be to simply convert the ppm file to
>another format supported by POV-Ray (eg. png).
>
Thanks for the "earthly or secular :-)" tip but I was just checking something
for the Moray Beta test when I came across this.
PS I liked your "Why is English so hard to learn" thread in Off topic

Regards
        Stephen


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From: Thorsten Froehlich
Subject: Re: Heightfield Type problems.
Date: 17 Mar 2003 08:43:09
Message: <3e75d0ed$1@news.povray.org>
In article <3e75c4f9@news.povray.org> , Warp <war### [at] tagpovrayorg>  wrote:

>
>   A temporal work-around would be to simply convert the ppm file to
> another format supported by POV-Ray (eg. png).

Given that it is generated with POV-Ray in the first place, generating it in
a reasonable compressed format like PNG directly makes more sense anyway.

    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: Heightfield Type problems.
Date: 17 Mar 2003 10:05:50
Message: <3e75e44e@news.povray.org>
Tom Melly <tom### [at] tomandlucouk> wrote:
> Looks more like a temporary work-around to me.

  You are probably right. :P

-- 
#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: Jim
Subject: Re: Heightfield Type problems.
Date: 25 Apr 2003 11:40:08
Message: <web.3ea955fcddef4d9036ddc6200@news.povray.org>
Hi,

   Just in passing, it has been my experience that most programs do not
support all the features of the NetPBM suite. In particular, the 16-bit
option and the ASCII option. Many programs put restrictions and limits
on the header that do not exist. The original intent was to make the
format as flexible and easy to read as possible.

Thanks,
julian


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