The Visual Walking System Of JiLin University

The traditional campus's three dimensioual illustration is alwaystoo simple and lacks the realness .As a result its practical value is oftenlimited .At present the simulation technology based on virtual reality isa hot issue research problem. Introducing virtual reality technologyinto the research of numerical campus can provide a new methed forcampus design and planning.Virtual campus three-dimensional modelshadol not only offer the natual ,real,visual and vivid representation ofreal world with strorg visual stimulation effect on the viewers but alsopreseat abundance.Based on a large ameant of foreign and domesticinformation,the summary of development and application of vistasimulation technology within and outside ear country,the combinationwith the campus's specific situation and the charouteristics andcomposition of campus simulation. This paper introduces the development,composition and its designindex of virtual campus simulation technology.This paper alsoestrblishes virtual campus roaming system.Three dimensionalreal-object model –building devecops vista simulation system withvirtwl reality's characteristics and realices the real-time simulation andthe inter-control funetion It analyies the key technology in modelbuilding and vista drive .The main contents of this research is thefollowing:1. It explains the necessity and proutical signficance of this research and puts forward the methed to realize virtual campus roaming system on the basis of the swmnary of the researth and application of visral smimulation technology with and out side our country .2. It establishes the campus's virtual scene with the use of large model-building software Multigen Creator. The scene model building methed of describing three-dimensionalobjects on the basis of geometry level structure and property canensure the control over the apex and surface of an object and can allowthe direct operation on the set leval data.As a result the model buildingprocess becomes easy and quick. The use of LOD tcechnology can simplize the geometry modeland scene,Thus the visual effect of the scene is guaranteed ,system'scost of drawing is greatly reduced,the speed of drawing scene's frame 71is increased and the system's real-time is improued, The aim of usingtexture mapping technology is to provide the real image effectwithout increasing the numer if polygon and to achieve the balancebetween the fidelity and runnin speed. On the other hand,toamplicated real object model texture mapping can simulate in greaterdetail,simplize model's constructing process,decrease. The complicated of real object model and give the model brightcolour and characteristics of mapping.the significance of texture canbe summarized as the following: it replaces the simulatable andnonsimulatable details of a real object model with images and increasethe vividness of simulation and presentation speed. 3, The use of visual drive software OpenGVS to Realizereal-time roaming explains the design process of scene roaming andanalyzes the key technology of vista simulation. In the collision detect algorithm based on the line of sight ,themost central algerithm is to intersection and it requires that thisalgorithm should not influence system's frame rate very much becaulea virtual scanning system hithout evident panee is of no value Themost important advantage of using envelope-box to do collisiondetection is its fast speed.Moreover,because the one-hundned percentprecision of collision detection during scenxe roaming is not nequired,it only needs to detect the collicion with the eavelope box. The algorithm to simulate rain and snow based on matrix partiedsystem realizes the real-time special efficacy and greatly increases thevividness of virtuel vista.This algorithm regard each rain-drop andsnow partical as a partical .All the particals scatler with in a certaine...