Håå, libGDX has a new 3D API? D:
I don't know much or anything really about the libGDX 3D API, perhaps you should ask in the libGDX forums?http://www.badlogicgames.com/forum/viewforum.php?f=11&sid=7a9e6a7721c97df6686b50aad5fbb8dd
SimplexNoise is an algorithm that can create pretty nice looking terrain and someone has been posting this pdf which I liked a lot: http://webstaff.itn.liu.se/~stegu/simplexnoise/simplexnoise.pdf
Simplex noise is an "improved" version of Perlin noise made by the same man (Ken Perlin) http://en.wikipedia.org/wiki/Simplex_noise
Basically when using noise you just take the values from the noise function and stick it straight to the height (z value if you will) of the terrain. You can have a couple of noise functions with different starting values and combine them to get "more realistic" terrain with a few high hills and oceans etc.