Abstract: A method and system for particle simulation are provided in which the number of particles is held as close as possible below a prescribed particle limit. When adding new particles to the simulation results in approaches the particle limit, new particles which contribute most to the visual quality of the simulation are added first, followed by deleting or merging existing particles which contribute least before adding the remaining new particles. Visual quality is also optimized by splitting particles into two or more new particles until the target particle count is reached. The criteria for performing insertions, deletions, splitting, or merging are governed by the results of predefined fitness functions by which the visual effect of each operation is estimated.