Many designers for the virtual world find it challenging to design efficiently believable complex textures or patterns on a large scale. Indeed, so-called “texture synthesis,” the design of accurate textures such as water ripples in a river, concrete walls, or patterns of leaves, remains a difficult task for artists. A plethora of non-stationary textures in the “real world” could be re-created in gaming or virtual worlds, but the existing techniques are tedious and time-consuming.