1. A method for computer graphics simulation of fluid flow of sparse fluids on a three dimensional surface using a processor, wherein the processor performs actions comprising: creating a partitioned two dimensional surface representing the three dimensional surface, wherein each partition of the two dimensional surface corresponds to a portion of the three dimensional surface; storing the partitions in a data structure; determining a normal vector for each partition in the data structure; determining a gravitational force vector for each partition; storing the gravitational force vector in the data structure; storing a fluid amount associated with each partition in the data structure; determining fluid flow on the two dimensional surface, including determining changes in the amount of fluid associated with each partition based at least in part on the gravitational force vector; wherein said determination of fluid flow includes accounting for fluid moving to and from neighboring partitions of each two dimensional partition; wherein the sparse fluid flow computations are performed only within partitions contained in the two-dimensional surface; reducing processor utilization while maintaining realistic animation based on said determined fluid flow on the two-dimensional surface; and visualizing the simulated fluid flow over the three dimensional surface in three-dimensional computer graphics for rendering on a display screen based on said determined fluid flow on the two dimensional surface, wherein the visualizing includes translating the fluid amounts per partition to visual characteristics of the corresponding portion of the three dimensional surface.