Hello,

I've read the documentation, FAQs, and gone through the Tutorial, but
haven't yet figured out the solution to my newbie problem.

I have a GPS receiver and an accurate altimeter, and wish to create a
simple, realistic 3D terrain model of about 300x300 meter land area by
walking around the area, while recording the X, Y, and Z (height)
coordinates.

GPS receivers typically produce WGS84 (geographic, lat/lon) coordinates, but
I have configured mine to provide Finnish KKJ (rectangular, XYZ)
coordinates, to make them compatible with POV-Ray's (rectangular)
coordinate system. The recorded "field data" files look like this:

<start of file>
6679290, 3385285, 30
6679296, 3385273, 26
6679275, 3385267, 42
....
<eof>

Each row describes a single measurement, where the first column is the north
coordinate ("X") in meters, second is the east coordinate ("Y") in meters,
and the last is height ("Z") from the sea level in meters.

Since there can be thousands of measurement points, I assume I should first
create a Java, Perl, etc. macro that automatically creates the .pov code
from the field data file. To make the .pov code generating as simple as
possible, I'd like to ask what is the simplest/best-suited POV-Ray's
"Terrain Object" to create this kind of realistic terrain in .pov syntax?
(Note: The field data is not necessarily in consequent order to easily
create "triangle mesh" by merging every 3 rows. Should it be to make .pov
generating easier?)

My goal is to produce something that looks like the Height Field Object's
example at http://www.povray.org/documentation/images/pvhfield.png - just
little more realistic :).

Thank you!

Lare Lekman
Finland

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would it be an idea to convert you're altitude into a gray scale and then
generate a picture with the data. you could then use that as a heightfield
(don't have any experience with this yet, but the documentation should
provide all the information you need)... you'd just have to write a little
program that can create a bitmap for you (or do these exist?)
"Lare Lekman" <lar### [at] yahoocom> wrote in message
news:web.3d5f9303bffdb24ae31a93b30@news.povray.org...
> Hello,
>
> I've read the documentation, FAQs, and gone through the Tutorial, but
> haven't yet figured out the solution to my newbie problem.
>
> I have a GPS receiver and an accurate altimeter, and wish to create a
> simple, realistic 3D terrain model of about 300x300 meter land area by
> walking around the area, while recording the X, Y, and Z (height)
> coordinates.
>
> GPS receivers typically produce WGS84 (geographic, lat/lon) coordinates,
but
> I have configured mine to provide Finnish KKJ (rectangular, XYZ)
> coordinates, to make them compatible with POV-Ray's (rectangular)
> coordinate system. The recorded "field data" files look like this:
>
> <start of file>
> 6679290, 3385285, 30
> 6679296, 3385273, 26
> 6679275, 3385267, 42
> ....
> <eof>
>
> Each row describes a single measurement, where the first column is the
north
> coordinate ("X") in meters, second is the east coordinate ("Y") in meters,
> and the last is height ("Z") from the sea level in meters.
>
> Since there can be thousands of measurement points, I assume I should
first
> create a Java, Perl, etc. macro that automatically creates the .pov code
> from the field data file. To make the .pov code generating as simple as
> possible, I'd like to ask what is the simplest/best-suited POV-Ray's
> "Terrain Object" to create this kind of realistic terrain in .pov syntax?
> (Note: The field data is not necessarily in consequent order to easily
> create "triangle mesh" by merging every 3 rows. Should it be to make .pov
> generating easier?)
>
> My goal is to produce something that looks like the Height Field Object's
> example at http://www.povray.org/documentation/images/pvhfield.png - just
> little more realistic :).
>
> Thank you!
>
> Lare Lekman
> Finland
>

Post a reply to this message

No solution here but some advice:

- subtract a constant from the x and y coords so that they start with 0,0 at
a corner.  this will make the numbers more readable and allow you to scale
correctly.

- Each of your lines is a point in 3d space on the surface of your ground.
sence they are not nesecarly in order I would suggest putting them in order.
(This could be the real tricky part)  A spread sheat with Graphing ability
like excel might work well here.

- After the points are ordered you need to fit a surface to them.  most
likely this will mean some type of mesh, but I can also see using the poinst
to make a height field.  It would go something like this (I think) :

  asume an N x M Grid of pixels.  For each pixel, asign a height based on
the weighted averge of all known points (you original data) using the
1/(distance fom Point)^2  as the weight.  Again a spread sheat or Perl
script would help here.

I know this isn't real clear but, maybe it will help
JFMILLER


"Lare Lekman" <lar### [at] yahoocom> wrote in message
news:web.3d5f9303bffdb24ae31a93b30@news.povray.org...
> Hello,
>
> I've read the documentation, FAQs, and gone through the Tutorial, but
> haven't yet figured out the solution to my newbie problem.
>
> I have a GPS receiver and an accurate altimeter, and wish to create a
> simple, realistic 3D terrain model of about 300x300 meter land area by
> walking around the area, while recording the X, Y, and Z (height)
> coordinates.
>
> GPS receivers typically produce WGS84 (geographic, lat/lon) coordinates,
but
> I have configured mine to provide Finnish KKJ (rectangular, XYZ)
> coordinates, to make them compatible with POV-Ray's (rectangular)
> coordinate system. The recorded "field data" files look like this:
>
> <start of file>
> 6679290, 3385285, 30
> 6679296, 3385273, 26
> 6679275, 3385267, 42
> ....
> <eof>
>
> Each row describes a single measurement, where the first column is the
north
> coordinate ("X") in meters, second is the east coordinate ("Y") in meters,
> and the last is height ("Z") from the sea level in meters.
>
> Since there can be thousands of measurement points, I assume I should
first
> create a Java, Perl, etc. macro that automatically creates the .pov code
> from the field data file. To make the .pov code generating as simple as
> possible, I'd like to ask what is the simplest/best-suited POV-Ray's
> "Terrain Object" to create this kind of realistic terrain in .pov syntax?
> (Note: The field data is not necessarily in consequent order to easily
> create "triangle mesh" by merging every 3 rows. Should it be to make .pov
> generating easier?)
>
> My goal is to produce something that looks like the Height Field Object's
> example at http://www.povray.org/documentation/images/pvhfield.png - just
> little more realistic :).
>
> Thank you!
>
> Lare Lekman
> Finland
>

Post a reply to this message

On Sun, 18 Aug 2002 08:28:51 EDT, "Lare Lekman"
<lar### [at] yahoocom> wrote:

><start of file>
>6679290, 3385285, 30
>6679296, 3385273, 26
>6679275, 3385267, 42
>....
><eof>

This should be dead simple to do with gnuplot's fit surface abilities.


Peter Popov ICQ : 15002700
Personal e-mail : pet### [at] vipbg
TAG      e-mail : pet### [at] tagpovrayorg

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