I am a beginner in three.js, so pardon me if this question is a little high-level.

I want to render a map in bird's eye view, and based on the value (e.g. color) on the map, I want to render and add a different object (e.g. a house, tree, rock) at that location. For example, if the map area is green, I would render and add a tree there.

Essentially, I'm trying to figure out how the rendering on this site is done. As far as I can tell, they have some terrain data in maps that are colored by land use. What I'm trying to figure out is how they use that information to render the cool houses and trees.