Abstract: We address the problem of Multi-Phase (or Many-Phase) Fluid simulations. We propose to use the regional level set (RLS) that can handle a large number of regions and materials, and hence, is appropriate for simulations of many immiscible materials. Towards this goal, we improve the interpolation of the RLS, and develop the regional level set graph (RLSG), which registers connected components and their contacts, and tracks their properties such as region volumes, film life times, and film material types, as regions evolve, merge, split, or are squeezed into films. Using RLSG's tracking feature, we generate particles from tiny regions or rupturing films.