“…With Lagrangian methods, such as front-tracking [20], immersed-boundary [21], or arbitrary Lagrangian-Eulerian (ALE) [22] methods, the interface is represented explicitly by conforming discretization elements. Although these methods have been extended to multi-region systems [23,24,25,26,27,10], it is difficult to handle complex topological changes during interface-network evolution, especially in three dimensions. With Eulerian methods, such as volume-of-fluid (VOF) [28] and level-set methods [29], the interface is reconstructed from scalar fields, i.e., volume fraction or levelset field.…”