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From: Andrea Ryan
Subject: Height fields
Date: 19 Jan 2000 20:33:25
Message: <38866311.10D78D0B@global2000.net>
Is there any way of finding the height of a height field at a given
point?
Brendan Ryan


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From: Chris Huff
Subject: Re: Height fields
Date: 19 Jan 2000 20:57:54
Message: <chrishuff_99-F65263.20582319012000@news.povray.org>
In article <38866311.10D78D0B@global2000.net>, Andrea Ryan 
<ary### [at] global2000net> wrote:

> Is there any way of finding the height of a height field at a given
> point?

Not without a patched version. The usual method is to use MegaPOV and 
the trace() function, I think this is explained well in the 
documentation for this patch.
MegaPOV is available at http://nathan.kopp.com/patched.htm

-- 
Chris Huff
e-mail: chr### [at] yahoocom
Web page: http://chrishuff.dhs.org/


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From: Margus Ramst
Subject: Re: Height fields
Date: 19 Jan 2000 21:00:45
Message: <38866CC4.D79081D@peak.edu.ee>
Not in official POV. You can however do it with the trace() function in the
Superpatch and MegaPov.
The syntax is trace(Object,Point,Direction,[Normal])
The function traces a 'ray' from a specified point in a specified direction and
repots the intersection point (if any) with the specified object. Optionally, it
can also return the surface normal at this point (see patch documentation for
details).
Now, from the XZ coordinates of the desired point, trace straight up towards the
HF, and you get the height at these coordinates.

Margus

Andrea Ryan wrote:
> 
> Is there any way of finding the height of a height field at a given
> point?
> Brendan Ryan


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From: Ken
Subject: Re: Height fields
Date: 19 Jan 2000 21:10:02
Message: <38866CEE.8D77E107@pacbell.net>
Andrea Ryan wrote:
> 
> Is there any way of finding the height of a height field at a given
> point?
> Brendan Ryan

Not in the official version of the program unless you use an external
utility like Leveller. MegaPov or the SuperPatch have the trace()
function that Ron Parker added that will allow you to do this.

-- 
Ken Tyler -  1300+ Povray, Graphics, 3D Rendering, and Raytracing Links:
http://home.pacbell.net/tylereng/index.html http://www.povray.org/links/


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From: David Fontaine
Subject: Re: Height fields
Date: 19 Jan 2000 23:24:30
Message: <38868B6B.DA9602DB@faricy.net>
42 minutes, Ken. Not good. *shakes head*

--
Homepage: http://www.faricy.net/~davidf/
___     ______________________________
 | \     |_       <dav### [at] faricynet>
 |_/avid |ontaine      <ICQ 55354965>


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From: Peter Popov
Subject: Re: Height fields
Date: 20 Jan 2000 00:33:52
Message: <tZ2GOJxtzUipMf0IdPFGkTAuRxUR@4ax.com>
On Wed, 19 Jan 2000 20:21:21 -0500, Andrea Ryan <ary### [at] global2000net>
wrote:

>Is there any way of finding the height of a height field at a given
>point?
>Brendan Ryan

You can do it in the official version but it's quite a heavier
solution than using trace(). Convert the hf source picture to ppm,
then use search/replace to replace all white space with commas, and
then use the file i/o functions in POV to read it into a 2D array.


Peter Popov
pet### [at] usanet
ICQ: 15002700


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From: Bill DeWitt
Subject: Re: Height fields
Date: 20 Jan 2000 01:08:17
Message: <3886a651@news.povray.org>
"Peter Popov" <pet### [at] usanet> wrote :
>
> You can do it in the official version but it's quite a heavier
> solution than using trace(). Convert the hf source picture to ppm,
> then use search/replace to replace all white space with commas, and
> then use the file i/o functions in POV to read it into a 2D array.
>

    Great, now I don't have to try to figure out how to do that. I knew
there must be a way, and I was looking at the file information of a TGA in
an attempt to find it...


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From: Remco de Korte
Subject: Re: Height fields
Date: 20 Jan 2000 06:03:32
Message: <3886EAEB.6CD7DC3D@xs4all.nl>
Peter Popov wrote:
> 
> On Wed, 19 Jan 2000 20:21:21 -0500, Andrea Ryan <ary### [at] global2000net>
> wrote:
> 
> >Is there any way of finding the height of a height field at a given
> >point?
> >Brendan Ryan
> 
> You can do it in the official version but it's quite a heavier
> solution than using trace(). Convert the hf source picture to ppm,
> then use search/replace to replace all white space with commas, and
> then use the file i/o functions in POV to read it into a 2D array.
> 
> Peter Popov
> pet### [at] usanet
> ICQ: 15002700

I reckon you could use the updated TGAMosaic to do that for you.
Otherwise I have a similar little utility (less powerfull) that'll make
an INC file of an image, giving you all the data you need. 

Remco


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From: ingo
Subject: Re: Height fields
Date: 20 Jan 2000 07:47:42
Message: <8EC181D42seed7@204.213.191.228>
Remco de Korte wrote:
>...
>Otherwise I have a similar little utility (less powerfull) that'll make
>an INC file of an image, giving you all the data you need. 

Sounds interesting, do you have it on your site?
What I'm actually looking for is something that generates "raw" data: the 
number of horizontal and vertical points and an array of rgb-values.


Ingo

-- 
Photography: http://members.home.nl/ingoogni/
Pov-Ray    : http://members.home.nl/seed7/


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From: Remco de Korte
Subject: Re: Height fields
Date: 20 Jan 2000 08:11:39
Message: <388708F2.6012D124@xs4all.nl>
ingo wrote:
> 
> Remco de Korte wrote:
> >...
> >Otherwise I have a similar little utility (less powerfull) that'll
> make
> >an INC file of an image, giving you all the data you need.
> 
> Sounds interesting, do you have it on your site?
> What I'm actually looking for is something that generates "raw" data:
> the
> number of horizontal and vertical points and an array of rgb-values.
> 
> Ingo
> 
> --
> Photography: http://members.home.nl/ingoogni/
> Pov-Ray    : http://members.home.nl/seed7/

I haven't tried TGAMosaic (yet); doesn't that do the trick?
Otherwise you can get the utility at my page
(http://www.xs4all.nl/~remcodek/pov.html). Look for ImagInc. It only
supports BMPs right now, but it'll be easy to put in other formats (as I
did with Bumper). The INC-file it spits out has 3 2-dimensional arrays,
for the R-, G-, and B-component of each pixel. You can change the
resolution (use low ones for testing). The melting rings and tentacle
thingies were made with this.

Remco


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