ABSTRACT
Simulating with a grid is quite different from the particle-based framework. The grid is like an array of fixed windows. For each point in time, data are recorded through the windows. You can also think of it as a digital camera that records a scene with a pixelated image. From a fixed point of view, physical quantities are captured at each grid point. As mentioned in Section 2.1, such a way of discretizing the world is called Eulerian framework, whereas the particle-based simulation is one of the Lagrangian methods. Note that there are methods in which grids move like particles. Those methods are either Lagrangian or Lagrangian-Eulerian hybrid, and they often use triangular or tetrahedral meshes [12,111]. In this chapter, we will only consider fixed grids.
