Foliage painter is used to spawn trees, rocks and other objects on to the terrain surface, by hand or procedurally. Different from Unity built-in terrain, Polaris spawn trees as child game object, so you can easily edit them after spawning. The spawning system is also rules based, which mean you can use geometry information like altitude, slope angle and distance between trees to determine where to spawn. To enable Foliage painter, click on the Foliage tab in the Inspector or press F6.