A Unified Anisotropic Particle-Based Ocean Wave Simulation Framework for Marine Simulator Visual System

Abstract

It is urgent to improve the physical reality of ocean scenes in marine simulator for the maritime industry. In this paper, we propose a unified anisotropic particle-based ocean wave simulation framework for marine simulator. In the unified framework, a novel hybrid SPH method is applied to model the ocean waves, which combines a series of nonlinear density constraints and divergence-free velocity field constraints. By solving density constraints, the particle position distribution is directly adjusted to keep a constant density. Experiments show that the hybrid SPH method has advantages in compressibility and stability. Moreover, a novel stochastic fluctuating wind field model is integrated into the hybrid SPH method. The Perlin noise and a modified log wind profile are introduced to enrich the details of wind field. We also introduce a novel oil spill model for marine simulator based on number density, which can achieve a desired sharp density changes at interfaces between multiple fluids. For real-time surface reconstruction, we propose an improved anisotropic particle transformation method based on the distribution of the neighboring particles. The problem of particle deformation near the boundary is solved by our piecewise correction function, with the sharp features and anisotropy maintained. When calculating the covariance matrix and weighted position, the contribution of neighboring particles in other fluid phases is considered to eliminate gaps between multiple fluids in the oil spill scenes. The simulation results show that our unified anisotropic framework based on the SPH concept can easily integrate other models, has strong expansibility, and is very applicable to simulate complex ocean scenes. INDEX TERMS marine simulator, SPH, ocean wave, wind field, oil spill, anisotropic transformation.