Weather Simulation Of Visual System On Flight Simulator

Weather simulation such as raining, snowing, lightning, and 3D clouds is studied in this dissertation based on former research on flight view simulation.Weather simulation technology is an indispensable part of the flight view simulation, and its reality makes a direct influence overall effect of the system. The enhancement of the reality will result in the decline of system real-time .Therefore, in order to keep the system real-time and adapt to flight view simulation, the methods of weather simulation are proposed as follows.Snow falling and accumulating. Based on analysis of traditional simulation methods, this dissertation presents a new approach for simulation of snow falling and accumulating for large-scale scene. According to the nature, snow simulation is divided into two stages -falling and accumulating and different simulation methods are used. Rotation, dynamic texture, and dynamic color of particles are taken into account in the former stage, which greatly improves reality of simulation. Image noise is introduced in the later stage, which solutes the problem that the traditional methods cannot be used in the large-scale scene.Raining simulation. It is implemented based on snowing simulation, which adopts the technology of particle system. In order to improve visual effect, funnel model is imported. And the simplified particle construction is used to improve rendering speed.Lightning. On one side, the dissertation makes an analysis on the model of special effects in Vega software environment. Based on the analysis, we make a conclusion that it is difficult to simulate lightning in Vega. According to the relation between Vega and OpenGL, we find it is viable to simulate lightning in Vega by using OpenGL. On the other side, by introducing the technology of texture mapping into lightning rendering, a high-speed rendering method is proposed and implemented in Vega.3D Clouds. It is one of the difficulties. The dynamic generation of the clouds is implemented by particle modeling technology and its rendering is finished by impostor algorithm. However, reducing particle algorithm is introduced because of the compatibility with Vega.Experiment results show that the above methods do well in weather simulation and meet the real-time requirement of the flight simulation. Meanwhile, lightning and 3D clouds simulations are achieved under Vega environment and extend the function of special effects in Vega. Although all the experiments are made in Vega, the related thinking can be applied to other platforms.