City rendering

All city rendering information for The Sims Online is found in the game's cities folder. The information is held in the form of 2D bitmap images, where each pixel denotes a lot of land.

For each city:

./city_xxxx/
 * elevation.bmp - Grayscale: Pure black is the lowest point and pure white is the highest point.
 * forestdensity.bmp - Grayscale: Pure black is no trees, gray is some trees, white is more trees.
 * foresttype.bmp - See table:
 * roadmap.bmp
 * terraintype.bmp - See table:
 * thumbnail.bmp - Just a preview of the city. Not used ingame.
 * vertexcolor.bmp