Wilbur: Incise Flow vs Fluvial Erosion for World Creation

[waldronate]

Incise Flow should calculate its flow on the entire map, but only write in the selected area. Operating in this way is important to ensure consistency with or without selected areas.
Precipiton erosion, however, only drops agents inside the selection and only lets them do their job inside the selection (they terminate when they pass out of a selected area). Just programmer laziness, I guess.

If you're set on using Wilbur as a world creator, start by creating a world full of islands with no large land masses. Then output the individual islands using a projection centered on the island and process each individually. Seriously, though, that sort of processing is about as good as you'll get with Wilbur, even if you apply it to more continental-scale things.