Simulating Liquid Dynamics by a Particle-Based Method

There is much research focusing on natural phenomena simulation in virtual reality and computer graphics. Liquid is chosen as our research object, because it is one of the most common natural phenomena. A particle-based modeling method for dynamic liquid simulation is presented in this paper. In our approach, accurate solutions for the Navier-Stokes equations are first accomplished in an Euler-based grid at each time step. This returns a velocity field calculated based on the pressure solved from a converted Poisson equation. Finally, particle movements are advected through this velocity field in order to simulate the dynamics of fluid volume. Experiment shows that visual effect which can satisfy users requirement is achieved by this method. This application has promising potentials in the areas of movie making, computer games, virtual construction and virtual simulation in medicine, etc.

Preliminary Study on Voxel-Based Virtual Geographic Environment Representation

The expression of virtual geographic environment is based on the surface modeling, such as three-dimensional terrain modeling and rendering most of which are based on the polygon grid and 2D textured. In the expression of extreme terrain, such as caves, cliffs, canyons it seems powerless. However, the voxel-based terrain modeling has been more useful than polygon modeling expression in the field of real-time terrain deformation, extreme terrain simulation and geographic process expression. Furthermore, virtual geographic environment based on the traditional surface model is difficult to realistically simulate the real world which is volumetric. This paper analyzes the trends of the geographical environment representation, and discusses the typical voxel-based applications in natural phenomena simulation, terrain modeling and spatial process analysis. It provides the references for the integrative representation of the unified voxel and surface model, and for the construction of virtual geographic environment unified platform.