1. A system, comprising: one or more processors, and a memory coupled to the one or more processors and storing program instructions executable by the one or more processors to implement: receiving input specifying one or more texture distribution rules; applying the one or more texture distribution rules to create a texture map of a visual texture comprising an arrangement of one or more instances of each of one or more atomic texture elements of the visual texture; and storing data representing the texture map for subsequent application of the visual texture to an image, wherein the data representing the texture map comprises data representing one or more diffusion curves.