傅立成臺灣大學:電機工程學研究所林孟勳Lin, Meng-HsunMeng-HsunLin2010-07-012018-07-062010-07-012018-07-062009U0001-0808200919393100http://ntur.lib.ntu.edu.tw//handle/246246/188107摘要篇論文主要建構出基於粒子組成的海面波浪，這種波浪的特性是適合物理上與船體也就是剛體的互動模擬。我們的目標在於架構一個在虛擬實境中的即時動態模擬船舶駕駛系統，而我們提出了一些新的方法來達到這個目標。首先，為了模擬大自然中主要被風所吹動的海浪，我們試圖為風力的影響提出一個模型，而讓這風作用在粒子組成的海面上，自然地形成波浪的運動。同時波浪也會受到重力或是本身黏滯力的影響。我們對於流體的模擬主要是基於平滑粒子流體力學(SPH)方法，也會在論文中做相關的介紹。其次，我們必須繪製流體的表面，而我們介紹了一種使用軟性材質的網格來建構流體表面的新方法。接著我們計算跟處理剛體與流體、風力、海面間的互動碰撞來模擬船體的動態，如此可以獲得更真實的結果。最後，這個模擬系統可以整合到六自由度的史都華平台，而建構出一個虛擬實境中的船舶駕駛模擬器。鍵字: 虛擬實境、基於粒子組成的、海面波浪、風力、平滑粒子流體力(SPH)、流體表面、船舶模擬器Abstracthis thesis focuses on the construction of particle-based ocean waves, which can be applied to interact with the boat in physical simulation. The goal is to construct a real-time physical dynamic system of boat motion simulator for virtual reality application. We introduce a new method to create ocean waves with particle-based fluid. First, in order to simulate wind-driven ocean surface, we use a wind force model to simulate the effect of actual wind, and let the force act on the particle-based fluid to create waves animation. Additionally, fluid dynamics of waves are also influenced with gravity force or viscous force. The particle-based fluid simulation is based on SPH (Smoothed Particle Hydrodynamics) method, which is introduced in this thesis. Second, we consider the issue of drawing fluid surface, and present a new method to construct the surface with physically simulated cloth. Then we can create the interaction between solid, fluid, force, and surface to simulate the dynamics of the boat, and we can get more realistic results. Finally, this simulation can also be integrated with the 6 degree-of-freedom motion platform to build a ship motion simulator.eyWords: virtual reality, particle-based, ocean waves, wind, smoothed particle hydrodynamics (SPH), fluid surface, ship motion simulatorTable of Contents謝 I要 IIIbstract IVable of Contents Vist of Figures VIIhapter 1 Introduction 1.1 Background and Motivation 1.2 Related Works 5.3 Thesis Organization 9hapter 2 Particle-Based Waves Simulation 10.1 Smoothed Particle Hydrodynamics (SPH) 14.2 Field Quantity of Particle Fluid 16.2.1 Density 17.2.2 Pressure 18.2.3 Viscosity 19.3 Wind-Driven Waves 20hapter 3 Ocean Surface Construction and Rendering 26.1 Marching Cubes 27.2 Fitting with Cloth 31.3 Ocean Surface Rendering 34.3.1 Reflection and Refraction 35.3.2 The Fresnel Effect 37.3.3 Shading for Ocean 39hapter 4 Ship Modeling and Dynamics 43.1 Preliminary Rigid Body Dynamics 43.1.1 Position and Orientation 43.1.2 The Velocity of Rigid Body 47.1.3 Equations of Motion 48.1.4 Forward Euler Integration 50.2 Solid-Fluid Interaction 51.3 The Ship Modeling 53hapter 5 Implementation 56.1 Ocean Waves Modeling 56.1.1 Particle-based Fluid 56.1.2 Wind Force Modeling 59.2 Ocean Surface Construction and Rendering 62.2.1 Marching Cubes 62.2.2 Fitting with Cloth 64.2.3 GPU Shading 66.3 The Ship Modeling and Dynamics 69.4 Integrated Simulation Loop 73hapter 6 Experimental Results 75.1 Ocean 75.2 Ship 78.3 System Integration with 6-DOF Motion Platform 80hapter 7 Conclusions 83eference 851783359 bytesapplication/pdfen-US虛擬實境基於粒子組成的海面波浪風力平滑粒子流體力(SPH)流體表面船舶模擬器virtual realityparticle-basedocean waveswindsmoothed particle hydrodynamics (SPH)fluid surfaceship motion simulatorthesishttp://ntur.lib.ntu.edu.tw/bitstream/246246/188107/1/ntu-98-R96921007-1.pdf