Valleys Mapgen 2.0

(Why have I named the first version 1.0 and not 0.0 ?)

I think it's the first version that is really playable. There are now trees and plants, same trees and plants than in vanilla v6/minetest_game. Average generation time : 530 ms on my computer (the same computer since the beginning of the project).

Snow ! The snow is more frequent at high elevation. In fact, this is the temperature that defines snow, and the temperature depends on a noise, and on the elevation.
Tree biomes are defined from temperature and humidity, and also from numerous other parameters.

Complete list of the plants :

• Apple tree : in plains, sometimes in the mountains but not very high.
• Jungle tree : in wet and hot places, never at high elevation.
• Fir tree : in the mountains, often on snowy places, not always. They use the nodes of default pine tree.
• Grass : in plains, and mountains.
• Jungle Grass : usually near jungle trees, but not always.
• Papyrus : near sea or river, or in very flat plains.
• Dry Shrub : in desert, or near desert.
• Cactus : idem, but rarer.

Trees are generated differently than in default mapgen. They use PerlinNoiseMaps to create the leaves.