One "feature" of the erosion model in Wilbur is that it's a global process. In this sense, it means that each part relies on the other parts of the system and a trivial partitioning (for example, splitting into quarters) followed by processing won't yield the same results as processing of the whole surface.

One of the benefits of using the described multi-scale processing operations is that the global features are established when surface processing is quick. One of the problems with the multi-scale process is that results have some peculiar features that result from upscaling the lower-resolution system. It can also be tough to get a solid handle on how the final surface will look just by looking at the first few processed surfaces in the sequence.