Ok those biome maps looked too good to stop there. I improved them and added similar map renderers for altitude, precipitation and temperature. And it was a very good idea since lots of issues became instantly visible. The main issue is due to the use of fractional Brownian motion to generate the height map. While this produce a nice looking map, it has a major issue : altitudes are linearly spread on the altitude scale. That means if you use a -2000m – 4000m scale, altitudes between 0 and 500 m will represent only 8% of the map. This is totally wrong and unrealistic and has a big impact on temperatures and biome generation.

Here are the debug maps before the altitude fix :

altitude

temperature

shaded world

See how the land becomes very quickly mountainous, cancelling the effect of the hot temperature band around the equator.

To fix that, I applied a simple x^{^3} function on altitudes above sea level, flattening the 0-2000m part of the land. Here are the maps after the fix :

altitude

temperature

shaded

Now the mountains are more abrupt and there is more room for medium and high temperatures. There are still issues with temperatures and precipitation maps, but balancing all those parameters becomes much easier with such debug tools. Here are the corresponding biome and precipitation maps :

biome

precipitation