基于JONSWAP谱的改进Gerstner海浪模型

Improved Gerstner wave model based on JONSWAP spectrum

为提高航海模拟器的沉浸感和训练效果,提出一种对海浪仿真的逼真度进行改进的方法。利用改进的Gerstner模型基于海浪谱对JONSWAP谱和方向谱进行参数提取。利用提取的参数求得满足精度要求的足够数量的单元波模型后,利用快速傅里叶变换(fast Fourier transform,FFT)进行加速计算生成高度图。通过Perlin噪声叠加分形布朗运动(fractional Brownian motion,FBM)生成Perlin噪声扰动高度图。将两种方法计算出来的高度图进行叠加融合处理。采用二分逼近法进行海浪光线渲染,实现海浪场景的仿真。实验结果表明,提出的方法在保证实时性的情况下提高了海浪仿真的真实程度,克服了传统FFT算法仿真大规模海浪三维场景重复性高的问题。

In order to improve the immersion and training effect of the navigation simulator,a method to the fidelity improvement of wave simulation is proposed.The improved Gerstner model is used to extract the parameters of JONSWAP spectrum and the direction spectrum on the basis of the wave spectrum.After using the extracted parameters to establish the sufficient number of unit wave models that meet accuracy requirements,the fast Fourier transform(FFT)is used for the accelerated calculation to generate the height map.Perlin noise is superimposed onto the fractional Brownian motion(FBM)to generate the Perlin noise disturbance height map.The height maps calculated by the two methods are superimposed and fused.The binary approximation method is adopted to carry out the wave light rendering and realize the wave scene simulation.Experimental results show that the proposed method improves the real degree of wave simulation while ensuring real-time performance,and overcomes the problem of high repeatability of large-scale wave three-dimension scene simulation by the traditional FFT algorithm.