Real-Time Watercolor Simulation with Fluid Vorticity Within Brush Stroke

We investigate the watercolor brush strokes from the perspective of fluid dynamics and the pigments movement within the flowing water. We propose a method to plausibly simulate process of watercolor painting on rough paper including the diffusion effects on graphics processor. We present a method based on 2D fluid simulation using Navier-Stokes equations to simulate the ink diffusion. Intricate details of water flow are preserved by taking into account the vorticity, too. Paper roughness and structure are considered in our approach when evaluating viscous term. Finally, to compose multiple colored semi-transparent layers of brush strokes Kubelka-Munk theory is used.