Hi Jonathan,
I used osgdem to create a Terraindatabase from 2 image files (Heightmap and
Colormap). Is there any way to access the height information in a texture? I
need to do some calculations in the shader for which i need informations abount
the surrounding terrain height, at guessed that it would be the easiest to look
them up from a texture - but i only have the colormap in the *.ive files.
If you can relate scene units to real height in some way (say scene
units are meters and Z=0 corresponds to "H" meters above sea level) then
it's pretty trivial to do this without even having the height in a
texture. Just transform vertex coordinates to world space in the vertex
shader, output those in a varying, and in the fragment shader you'll
have the world-space location of your pixel. The Z of this will be the
height, relative to "H" above. You can pass "H" to the shaders in a
uniform that you set at your scene root.
If you're in a weird projection then I wouldn't know, but this should
work fine for flat-earth models I think.
Hope this helps,
J-S
--
______________________________________________________
Jean-Sebastien Guay jean-sebastien.g...@cm-labs.com
http://www.cm-labs.com/
http://whitestar02.dyndns-web.com/
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