DEM to terrain transformation

Europe theater

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Luk
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DEM to terrain transformation

Post by Luk » 2007-11-28 23:18:57

What type of transformation ("spherical conversion") does DEM2terrain exactly use please?

This is PMC Europe theater:
Image

I did my own elevation map, because of I am not able to export detailed elevation map of theater from DEM2terrain. I can set the colours for different highs very good inside DEM2terrain. But exported bmp doesnt respect my colours setting and it looks still the same - like on the picture above...
So I did another map, using 3DEM software.
But my new bitmap doesnt fit the theater of course. It has an other georeference system.
I have set cornes of the area(we know lat/lon), and then cropped the image:
Image
Can be I am making misstake already in this step, but I hope
data projection is still the same(cilindric), doesnt matter if I load them to DEMtoterrain or to 3DEM.
So I think the most preblematic is next step. Change this above shape ("trapezoid"?) to square (our theater).
I did it two times.
1) Deformation in bitmapeditor:
Image
2)I mapped image onto polygon in 3D program, them stretched and rendered. Result here:
Image
In both cases the cornes are good, but everything else is totally wrong :(
In conclusion:
a)what projection does use the data stored in this page:
http://www.ngdc.noaa.gov/ (from terrain tutorial)
b)Which transformation does DEMtoterrain software during mysterious "spherical conversion" - simple stretching doesnt work

Thank you
Luk

P.S.
I know, Arc gis software and similar can handle bitmaps much more clever using some reference points, but is there some simple way?

Closter
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Joined: 2007-01-07 00:13:42

Post by Closter » 2007-11-29 20:32:12

Perhaps these two threads could be of help to you:

viewtopic.php?t=20922

^----Pay attention to the end of page 1 and start of page 2. The rest is interesting also.

viewtopic.php?t=21003
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Luk
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Posts: 455
Joined: 2007-04-23 09:59:36

wow!

Post by Luk » 2007-11-29 23:07:43

Thank you very much Closter!
Your pdf is what I am trying to find! :D

I have red it all and it suggested me, that there
is a man (Blueprint) who is able to get a bitmap directly to/from "L" file!
Is it really true?

Luk

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