Hi tracers!

As I mentioned in an earlier posting, I'm currently working on an
elaborate landscape scene - intended to be the very
beginning of a 3D representation of a whole country, i. e. Afghanistan.

This initial heightfield already is 1250 x 1000, each pixel equals 25.4
by 25.4 metres. The texture for this heightfield will only
show the colors of the bare soil, not vegetation cover, but to provide
for really smooth gradients of subtle color variations,
I'm quite uneasy about using just a same-sized image map. In a
preliminary study last autumn, when I used a heightfield of a
mere 500 x 200 pixels, I got good-looking results only with an image map
of at least 10 times higher resolution in both
dimensions, i. e. 5000 x 2000 pixels - but with the current heightfield,
that would be pretty close to the limits of my computer
(only 256 megs of RAM).

Is there instead a way to to this in a procedural rather than a
pixel-based manner? The soil types would be depending on
altitude and/or steepness of slopes as well as closeness to rivers or
wadis/dry valleys, not to mention areas shown in the
original topographic maps as stony/sandy desert or salt flats. Some of
these soil types, such as river banks or dry valley floors
may also be composed of several sub-types combined in a texture map...

Any advanced landscape modeler around?

See you in Khyberspace!

Yadgar

Now playing: Oye mi canto (Gloria Estefan)

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Hi Yadgar!

From what I understand, you want a vegetation map with fine details that
fits your heightfield, but doesn't take up too much memory. Well you could
use a grey, low resolution image map (smoothed with "interpolate 2") as a
reference map, that doesn't really contain any textures, but only a
reference to *where* you want each texture.. Although the referance map is
low resolution, I doubt it'll be a problem..

The reference map point to any textures, depending on it's brightness, so
you can paint the vegetation in a paint program..

From old days, POV has texture maps that only works with GIF input.. I found
a nicer way with POV3.5 ... here is the basics to give you the idea:

texture {
  function { pigment {
    image_map { tga "...." interpolate 2 }
  }}
  texture_map {
   [ 0.00 Soil ]
   [ 0.25 Grass ]
   [ ...etc ... ]
}}


Regards,
Hugo

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