Phenomenological Simulation of Brooks

Abstract : The goal of our work is to simulate the shape and variations of the water surface on non-turbulent brooks both efficiently and at very high resolution. In this paper, we treat only the shape and animation. We concentrate on the simulation of quasi-stationary waves and ripples in the vicinity of obstacles and banks, and more particularly, shockwaves. To achieve this, we rely on phenomenological laws such as the ones collected over the last two centuries in the field of hydrodynamics: most of the visually interesting phenomena (apart from turbulence) are known qualitatively and characterized in reasonably simplified situations. It is thus wasteful to run a full-range Navier-Stokes simulation for quiet flows when only qualitative results are needed. The complexity of the velocity field along the streambed and around the obstacles is taken into account by solving a simple Laplace equation, assuming a stationary irrotational non-compressible ideal 2D flow. We obtain a stationary solution of the surface waves, that we perturb in order to get a quasi-stationary brook simulation. This yields a real-time simulation of the fluid visible features.