In procedurally generated or procedurally augmented scenes, a common problem is how to scatter something around in a way that looks natural. For example, a landscape might have trees that are evenly scattered, either sparsely as on an African savanna or densely as in a forest. Also, trees are generally surrounded by other vegetation, which is also scattered.
Suppose you are tasked with developing algorithms to facilitate this scattering. This article looks at various approaches and problems you might encounter.