I have written a program to proceduraly generate and render a three-dimensional hex map. I also have a function to create "on the fly" the texture which gets texture mapped onto the landscape, but it''s not very good. Right now it just picks a color from a lookup table based on the elevation of the current point. It also throws in a little bit of noise so that edges between colors aren''t straight lines. This works well enough if you''re drawing the grand canyon (very layered effect) but I''m looking for something a little more detailed. I''d like to get a "sheer rock face" effect when the slope is steep and the altitude is high, a "grassy" effect for low slope low altitude patches, ...etc. A perfect example would be the effect used in Populous: The Beginning. Anyone have any experience with this, or thoughts?

Note: I don''t have any experience with landscape texture generation at all, but here are a few thoughts:

- Use bitmap textures (rock, grass, snow). Eventually make them grayscale and color them as you want. (reddish brown for the grand canyon, grey for the mount everest, and so on)
- Use a Perlin noise function for generation of the noise. This looks pretty good.

DaBit.

Hmm, the bitmap approach is an interesting thought. Of course I had considered using set tiles, but that was too boring. Using a bitmap as the base for a procedural texture might work out, but it begs one question... How to seamlessly "join" the "bitmap based procedural textures" at the boundaries between different types of landscape (snowfield to swamp for instance). I''ll have to think about this a bit more.

The snowfield to swamp case is not so hard, since there are two possibilities to make the transition. One is a hard edge at the intersection line of tne snow and the swamp. At a snow/water boundary this can happen. Two is that there is an overlap between snow and swamp. You can model this by using a fractal function such as ''plasma/cloud'' and using that in combination with a treshold to create ''puddles'' of snow on the swamp. Every value coming out of the fractal function above the treshold is snow, everything under the treshold is swamp. The deeper you enter the swamp, the more you adjust your treshold, so the ''puddles'' of snow get smaller until they disappear.

This probably works, but gives a very unnatural feeling. To reduce this, use a noise function to adjust the treshold a bit. The human eye is very sensitive to regularity, while in nature there is not much real regularity.

Again: just my ideas. I never did anything with this kind of stuff, although I did play with fractals and noise.

DaBit.

I don''t think that would be unnatural at all... The lienar drop off of the threshold should be disguised by the noise funtion it''s being applied to... Actually, I think that''s a brilliant idea. It''s starting to sound a bit CPU intensive for a quasi-realtime texture, but I think it''s worth a shot... Thanks a lot!

http://www.threedgraphics.com/texsynth/