Dynamic Fountain And Dynamic Water Effects Rendering In Virtual Reality

With the rapid advance of computer performance and continuous improvement of virtualreality technology, it is possible to achieve photorealistic rendering through general PC. Thispromotes the constant expanding of the virtual reality technology application field. Waterlandscape is the most common natural view on the earth, and water effect simulation becomesa difficult point in virtual reality field due to morphological diversity of the water. As a resultof the extensive existence of water, the water simulation is an inevitable part in the generalvirtual reality system. Most scholars use dynamic texture technology in fountain simulation,which makes the fountain seems to be insufficient in flexible and realistic levels. Forsimulating more realistic and more vivid fountain effect, particle system technology has beenused to simulate the fountain effect in this dissertation. Recently, water fluctuationstechnology has made great achievements, however, the algorithm becomes complex duringcontinuous development so that the rendering time gets longer. In this dissertation, theexisting surface fluctuation algorithm has been improved to enhance the speed of watersurface rendering.During the further research of the particle system simulation fountain technology, theresearch mainly consists of four control fountain components namely the particle emitter,linear force effector, the collision, and color modifier. The components control the productionof particles, air movement of particles, collision of particles, and color of particles. There aretwo main decisive factors in the design of the fountain reality: the color of fountain particlesand the shape of the fountain appearance. Consequently, there are a plenty of experimentalresearch in this two effects designs. In the end the color modifier is chosen to control the colorand shape of fountain, and the design is accessing to the fountain color effect in the real world.The research found that only the particle emitter and linear force effector have influence onthe appearance of the shape of a fountain, so all parameters that control these two componentswere changed in the comparison test, and the final experimental results show that there arethree parameters affect the fountain shape directly as follows: the maximum angle of initiallaunch, initial launch speed, and the vertical component of the linear force effect. Eight fountain effects which meet the real-time rendering requirements are simulated based on thestudy of the impact of fountain effect, then the fountain effect codes have high versatility andportability.The research of simulating dynamic water effect focuses on three aspects, which includesthe sea wave propagation simulation, the lighting effects simulation, and water causticsphenomenon simulation. A rough sea surface fluctuation effect was achieved by usingGerstner wave based on waveform analysis at first. In order to satisfy features of the sharppeaks and wide troughs of a wave in the real world, the influences of steep parameters’changes on the wave form in Gerstner wave have been discussed. The diffuse and specularreflection of the basic lighting model has been corrected with a distance attenuation factor inimproved lighting model. As a result，the lighting effects become more real. Finally, there aretwo simplifications in the traditional light reverse tracking algorithm: one is the test ofwhether all the water-injection light coming from the sun are detected by the view angle to thesun at any point on Earth, and the other one is calculation of vertical light according to thedirect distance and lest consumption theories. Moreover, a water caustics effect is realizedwith the modified method, which meets the requirements of the formation of sunlight on thesurface.