3d Rendering Technique Based On Virtual Reality And Practice

Since 1990s virtual reality technique has been one of the hot spots in IT field.It creates a living virtual environment by using computer and allows the users communicate with it freely.Now VR is widely used in the military,medicine, education,virtual travel,shopping,interactive entertainment etc.As a modeling language,VRML is regarded as the second generation of web language aiming at constructing interactive 3D multi-media on Internet. It can be used to describe attributes and behaviors of 3D objects,create virtual world, integrate texts,pictures,sounds,MPEG and so on.It can also be embedded with codes programmed by Java,JavaScript languages and makes the design of VR become more efficient.It is very popular to use VR in designing districts, city plans by virtual roaming technique.Roaming System is a virtual environment in specific ranges which includes vivid vision,hearing and feeling in one.Using some necessary equipments, users can walkthrough in this virtual world or observe virtual objects from any angle and they will feel themselves in the scene.They can also operate the objects inside virtual environment.Virtual walkthrough system is the integrated application of virtual reality skills,which has a promising future.In this paper, we briefly introduce some relevant techniques of VR and VRML, then put our focus on the research of virtual walkthrough,including 3D scene modeling,scene optimizing etc.finally we design and implement a virtual campus walkthrough system based on PC.The following is the content of this paper:.Chapter 1 brief introduction to the basic concept of virtual reality and characteristic of it.Then expatiate the background,meaning,content and goal of our project.Chapter 2 introduce the principle and system architecture of VRML,especially focus on the important concepts, such as node, scene graph structure, event system and extended mechanism.Chapter 3 discuss virtual walkthrough technique.First of all introduce the concept of walkthrough system,then analyze and compare the two techniques of how to implement virtual walkthrough(geometry-based modeling and rendering—GBMR and image-based modeling and rendering—IBMR),at last probe into the techniques of 3D scene modeling and optimizing algorithm,preparing for the next chapter. Chapter 4 describe a designing and implementation of virtual campus walkthrough system based on VRML in detail,especially focus on the scene modeling and some optimizing measures of how to improve scene rendering speed.Chapter 5 conclusion of the result of experiments and looking forward to the next task.