Application And Research Of OpenGL In The System Of Traffic Simulation

With the quick development of society economy and continuousacceleration of urbanization process, urban vehicle population continues toincrease and urban traffic demands increase sharply. Many problems abouttraffic that includes traffic congestion, traffic accidents and environmentalpollution have become a universal problem. It's not enough to improve theinstance of urban traffic just through building roadways more and morebecause the increase speed of traffic demand is faster than the increase speedof roadway building. The government needs to lead the traffic demand, adjustthe structure of roadway network in time, develop the public traffic actively,improvethemanagement abilitystepbystep,andimprovetheabilitybasedoninformationespecially.Thesystemoftrafficsimulationisusefultoobserveallkinds of traffic instance visually such as traffic flow, analyze the trafficcharacteristic, and carry through traffic study effectively. It's possible toobtainusefuldatawithlowcostthroughsimulation.Simulationisusefulinthestudyoftraffic.The system of traffic simulation has much merit. It's convenient andcheap without the participation of real system. The system can tell whichvariable of traffic is important. It's efficient to study the dangerous instancesuch as traffic accident with the system of traffic simulation. The system canjudge which design of layout is better through offering the same trafficcondition. It can forecast the behavior under all kinds of conditions throughthe change of the running conditions of the system. The system can forecastthe traffic congestion. It can be very useful when other technique can't solvethe problems. The system of traffic simulation can forecast the instance ofurban traffic, so the running status about the roadway network of city can beimproved, basic establishment of traffic in existence can be used well andeffectively, traffic congestion can be relaxed, and it's possible to cut down the environmental pollution, save energy and improve the secutity of driver.Traditional measure of traffic layout and management system apply themethods of mathematic analysis, and they are not fit for the demands ofmordentrafficintheaspectsofsolvingthecomplexsystemabouturbantraffic.Comparedwiththe methodsofmathematicanalysis,thetechnique of simulantanalysis can describe the difference among each traffic entity particularly andpresent the process of urban traffic, so that it's convenient to study thedynamic performance of compex system from the angles of time and roomsynchronously.Thetechniqueofsimulationhaspowerfullifeandlatentabilitybecauseofitshighefficiency,highqualityandlowcost.It's necessaryto draw the roadwayelement, cars and traffic lamps at thetime of traffic simulation. Drawing with the technique of OpenGL isconvenient and the picture is visual. OpenGL can deal with three-dimensionalmodel, so it can draw three-dimensional vision that is very similar to theexternal world. OpenGL can process three-dimensional alternation, actionsimulation and so on. The main function of OpenGL includes model drawing,model observation, appointment of color mode, application of illumination,enhancing of image effect, bitmap and image manipulation, texture mapping,realtimecartoonandtechniqueofalternation.Comparedwiththeothertoolofimage development, the merit of OpenGL is as follows: Firstly, it has broadapplication. At the present time, OpenGL is one of the most populardevelopment tool of program that can deal with two and three-dimensionalalternation. OpenGL is used in all kinds of field, and it becomes the mostpopular interface of image applications. Secondly, it has high quality andperformance.OpenGLapplicationscandrawthree-dimensional imagethat hashigh quality in despite of the development platform. All the applications thatpursue the highest drawing effect and efficiency can benefit the high qualityand performance of OpenGL. Thirdly, its programming performance isexcellent. OpenGL has sufficient independence. OpenGL has become imagestandardthatisopenandindependentwithplatform.It'ssteady,telescopicandconvenient. Fourthly, it's realized on many platforms and independent withhardware system. Fifthly, OpenGL is transparent about network. A process of a workstation with OpenGL technique can display image on local machine orother machine on the network. OpenGL can disperse the task ofthree-dimension processing on manycomputers. OpenGL technique is used atthetimeofdevelopingthesystemoftrafficsimulationbecauseofitsmerit.This paper depicted the design of the traffic simulation system andpresented the detailed realization about each function module of the systemwith OpenGL. The system of traffic simulation includes four modules,roadway network editing, view controlling, simulation of traffic scenario, anddatabase operation. There are many roadway network elements such ascommon roadway, channeled roadway, linker, traffic light, detection winding,vehicle point, intersection, swerve flag of roadway, scutcheon of variationalinformation, public station, public route, rule of giving way, parking sign,accident area, decelerating area, parking area. The view of system can bemagnified in order to display some local part clearly. User also can dwindlethe view for the sake of holding the whole well. At the time of roadwaynetwork editing, bitmap can be loaded, rotated, hidden, moved, and zoomed.User can control the simulation process, such as single step simulation, pause,stop of simulation, accelerating the simulation speed, and decelerating thesimulation speed. The module of database operating includes save and readfunctions. The interface of this system is friendly and wieldy. The image isvisual, vivid, and intuitionistic when displaying the running status about thevehicles on the roadway network. It's very easyto find which part is crowdedand which part is fluent. This system is helpful when studying dangerousinstance or catastrophic aftereffect of the traffic system, forecasting thebehavior of the traffic system under all kinds of condition, and predicting thetrafficcongestion.