Hi guys,
I'm using my Perlin Noise algorithm as a height map (I don't store as a texture, I use the values directly on my vertices).
Representing an earth scale planet I need a height map for at least 510 million km².
My problem is now, that I don't know how to make a "more detailed" noise on higher LOD.
There must be another way than making an array of 32000*32000 random numbers for perlin noise to get acceptable terrain on highest LOD.
Are there any techniques to get this done?
LOD with Perlin Noise "zoom"
Don't use a random function, rather use a hash function to generate the noise values. That way each point can be calculated independently of any other point, making LOD quite easy.
Straight-up Perlin noise is a rather uninteresting sinusoidal curve. To generate a perlin-based terrain, one usually combines multiple octaves (layers) of perlin noise together, while varying the frequency/scale of each octave. Look around for "fractal brownian motion", or "ridged multifractal" for a few common such fractals.
I'm assuming you are already using such a multi-octave noise function, in which case, to increase detail at higher LOD, you just add successively more octaves of noise.
I'm assuming you are already using such a multi-octave noise function, in which case, to increase detail at higher LOD, you just add successively more octaves of noise.
Author
Hi swiftcoder. Thanks for the keywords
"fractal brownian motion" and "ridged multifractal" thats exactly what I was looking for! Now I got tons of new material 
[color=#282828][font=helvetica, arial, verdana, tahoma, sans-serif]NEW Question:[/font]
[color=#282828][font=helvetica, arial, verdana, tahoma, sans-serif]Is the only way to get a seamless cubemap for terrain, to generate 3D noise? Or is there an algorithm to map 2D data seamless on a cube? [/font]
Is the only way to get a seamless cubemap for terrain, to generate 3D noise? Or is there an algorithm to map 2D data seamless on a cube?
One can come up with a number of kludgy solutions using tiling 2D noise and a polar projection, but nothing that works terribly reliably.
I always end up using 3D noise for my procedural planets - it just looks and works better.
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