Visually appealing water flow over a terrain

This project implements a program to simulate water flow over terrains. As in many other computer graphics applications, we look for reasonably fast computation and rendering. So the prediction of exact quantities as stated in physical laws is not our goal. However to ensure our results look visually appealing, we still need to apply the physical laws to a certain extent so as to account for several characteristic features of the phenomenon, including water flow, soil erosion and deposition, and evaporation. Which physical laws to use and how much they should be simplified are challenges facing us. The framework introduced by Benes et. al. [Benes and Forsbach 2002], which is later extended by Anh et. al [Anh et al. 2007], is our final choice. It is which we find to-date balancing the two conflicting requirements well. The model adopts a layered data structure to store the elevation, water volume, dissolved material volume and water velocity of every grid point of the terrain. Every simulation step is discretized into a few operations to decide how much soil gets eroded, which direction(s) the water should flow, how much soil should be deposited, and how much water to be evaporated.