Fluid surface detail protection method based on grid and particle coupling

Abstract

The invention relates to a fluid surface detail protection method based on grid and particle coupling. The fluid surface detail protection method comprises the following steps: (1) solving a Navier-Stokes equation (N-S), and forming a simulation model of a main body fluid by adopting a grid method; (2) improving an LBM-VOF method, and tracking the surface of the fluid by using an improved VOF-LBMcoupling algorithm; (3) generating particles at the abnormal surface grid position, and then evolving the particles through a particle method; (4) designing a coupling algorithm of grids and particles, and integrating grid fluid and particle fluid into the same scene so as to ensure physical conservation of the whole flow field and reasonable physical information transmission between the grids andthe particles; and (5) finally, performing realistic rendering by using a screen space method, and realizing realistic and real-time fluid rendering on the GPU by drawing a sphere, calculating a depth value of each pixel point, performing depth filtering, solving a normal vector according to the depth values and position information of the pixel points, and performing illumination rendering. Realistic and real-time fluid rendering is realized on GPU.

Description

technical field [0001] The present invention relates to a method for protecting fluid surface details based on mesh and particle coupling, in particular to a physics-based graphics animation simulation method, and some of its technologies involve building a high-precision main body fluid simulation model, building and LBM Coupled fluid free surface tracking model, generation and evolution of particles, coupling algorithm of mesh and particles, and related theories of mechanics. It is mainly used in three-dimensional realistic simulation of various real objects, especially in entertainment games, movie special effects and other fields. Background technique [0002] In recent years, one of the hotspots and difficulties in the field of computer graphics research is the simulation of realistic scenes, animations and phenomena, which are widely used in manufacturing engineering, film and television special effects, 3D animation, computer games and virtual reality and other fields...

AI Technical Summary

Problems solved by technology

The Lagrangian method, represented by SPH, is a particle-based method. It focuses on the motion tracking of fluid particles, considers the motion of all particles, and then forms the entire fluid motion. Its advantages are simple, intuitive, easy to understand, and can be simulated. The movement details of the fluid, but the amount of calculation is large, it is difficult to select a suitable smooth kernel function, and it is prone to distortion in the case of large deformation; the Euler method is based on the grid, it does not specifically track the specific movement process of a certain particle, but will flow field as object

The Euler method is beneficial to the analysis of physical field properties, it is easy to construct the liquid moving surface, and it can handle deformation and distortion problems, but it is difficult to express the surface details of the fluid; the LBM method is a "mesoscopic" fluid simulation method based on Euler. A large number of details of molecular motion are ignored, and only some statistical characteristics of molecular motion speed are retained. This method is easy to deal with complex boundaries, the algorithm is simple, and has a high degree of parallelism, but it is still a grid-based description method. At the same time, the detailed simulation There are still deficiencies

[0004] Literature 1-Koerner C, Thies M, Hofmann T, et al.Lattice Boltzmann Model for Free Surface Flow for Modeling Foaming[J].Journal of Statistical Physics,2005, 121(1-2):179-196, for the surface network In order to solve the problem of lattice reconstruction distribution function, a surface mesh reconstruction method based on the momentum exchange method was proposed, but the numerical accuracy of this method is low, and the visual effect of the surface mesh will vibrate in the equilibrium state. At the same time, literature 1 A set of special processing methods is also proposed for abnormal surface grids, which alleviates the problem to a certain extent, but it is difficult to guarantee the conservation of physical quantities

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