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| High!
|
| Once again, like already in December 2003, I tried to render a
spherical
| mesh (to be precise, a small section of a spherical mesh, covering only
| one square degree) from a 1200 x 1200 ASCII matrix generated itself
from
| a SRTM GeoTIFF (needless to say what part of the world ;-)).
|
| I hoped that my new Athlon 64 2800+ would be able to cope with it...
but
|  once again was disillusioned, after about 780 lines the parsing became
| so slow that it would have take millennia to parse the rest.
|
| Are there ways to speed things up? Christoph Hormann's HF_sphere macro
| would not be an alternative as it renders only complete spheres (unless
| there has been an update meanwhile, of which I don`t know yet), not
| sections.
|
	How much RAM do you have on your computer? My bet is that it gets to
a point where you use too much memory and the computer starts to swap.
You could use a lot less memory by doing away with the mtrix arry and
using a mesh2 (and gain in computational complexity during parse at
the same time).

	Try something like this (untested):

mesh2 {
~  vertex_vectors {
~    1200*1200,
~    #fopen matr "e:\homepage\n34e068-b.txt" read
~    #declare a = 0;
~    #while (a < 1200)
~      #declare b = 0;
~      #while (b < 1200)
~        #read (matr, data)
~        <(re+data) * sin ((sLong-b/1200) * (pi/180)) *
~         cos ((sLat - a/1200) * (pi/180)),
~         (rp+mtrix[a][b])*sin((sLat-a/1200)*(pi/180)),
~         (re+data) * cos ((sLong-b/1200) * (pi/180)) *
~         cos ((sLat-a/1200)*(pi/180))>,
~        #declare b = b+1;
~      #end
~      #declare a = a+1;
~    #end
~    #fclose matr
~  }
~  face_indices {
~    1199 * 1199 * 2,
~    #declare a = 0;
~    #while (a < 1199)
~      #declare b = 0;
~      #while (b < 1199)
~        <1200*a + b, 1200*a + b+1, 1200*(a+1) + b>,
~        <1200*a + b+1, 1200*(a+1) + b+1, 1200*(a+1) + b>,
~        #declare b = b+1;
~      #end
~      #declare a = a+1;
~    #end
~  }

~  texture {
~    pigment { color rgb <1, 0.5, 0> }
~    finish { F_Standard }
~  }
}

		Jerome
- --
******************************
*      Jerome M. Berger      *
* mailto:jbe### [at] ifrancecom *
*  http://jeberger.free.fr/  *
******************************
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