Abstract: Subgrid-scale fluid is difficult to represent realistically in a grid-based fluid simulation. We show how to describe such small-scale details effectively, even on a coarse grid, by using escaped particles. The simulation of these particles with SPH (smooth particle hydrodynamics) allows the illustration of dynamic and realistic animation of fluids. Particles modeled by SPH have a force which leads them to merge if they are within a certain range. This reduces the accuracy of a simulation. Consequently, aggregated particles which form volumes large enough to be described by the level set method will be simulated inefficiently by particles. We address this problem with a new method in which details too small for the grid are represented by particles, while the level set method with a grid is used to describe merged particles on the grid.