Virtual Simulation Technology In The Application Of City Planning

Virtual simulation technology can produce an artificially virtual environment inthe computer. The virtual environment is a kind of3D digital model which iscomposed by computer graphics and it can produce an artificial environment throughthe computer’s programming software. This kind of integrated sensible environmentmainly focuses on visual feeling, including auditory and tactile sensation as well.Thus, it can give you a feeing of immersing in the environment. One can directlyobserve, operate, touch and examine the outer environment and inner changes. What’smore, one can also interact with the environment so that it can make harmonize thehuman beings and computers and also give us an experience of being personally onthe scene. This technology can create a similar environment with the real society sothat it can resolve the circumstance of study and meet the need of natural interactivity.It has an extremely applicable prospect in the education field. As regard to theprospect of application, it has played a decisive role in video games, the militarysimulation training, GIS, simulated driving, digital city planning and other fields.When we talk about the application in the city planning,We can study it from the following aspects. Firstly, seeing from the threedimensional visualization, this technology can truly reproduce spatial relationshipbetween the planned building and existing ones by displaying the inter-relationshipbetween different constructive plans and the buildings around. Then, we can timelymodify the height, directing, mass, color and so on. This can help adjudicators andpolicymakers compare different planning cases from different observing point. It canalso assist the planners to confirm a reasonable plan more clearly and intuitively, so asto improve the managerial level of planning, and decreasing the faults and blindnessof decisions, making planning management more reasonable, scientific andtransparent. Secondly, seeing from the managerial function, virtual simulationtechnology consistently keeps pace with digital city planning in the course ofcontinuously improvement and it can make the latest digital city planning timely demonstrated in the formatting environment. Through this we can strengthen themanagement of digital city planning and emphasize the harmony between the planand the around areas. Lastly, seeing from direction of the expansion of the system,virtual simulation technology should become an effective, intuitive and reliableplatform among different sections of city management. It must keep pace with the realcity layout and have enough access for both software and hardware, and the modulefor function expansion as well. Therefore, it can be applied to the city trafficmanagement, public security service, disaster prevention and other fields.The Application of Three-dimensional visualization of virtual simulationtechnology does not exist as a single. It is a algorithm set of many aspects. Generallyspeaking, it contains the following four technologies: the model demonstrationtechnology, the technology of storing apex data, the quantum domination technologyof triangle (polygon), and the technology of simulating real environment in the reality.As for the application in the digital city planning, this thesis will realize it by usingNET and XNA in the basic technology structure. As regard to the specific application,the technology of model demonstration will be realized by3D Max, and thetechnology of storing apex data and the quantum domination technology of trianglewill be realized by the using of LOD. The simulation of real environment will berealized by using Shader3.0, Lightmap, indicator board, the sky box, the timelyshadow and foggy movement technology, and so on. This paper basically provides athree-dimensional engine by using XNA and.Net and it can run in a PC withxnafx40_redist. The difference between the traditional program is that this programneeds much advanced hardware to match it. In this thesis, a movement not less than30F/S in the computer can be assured. However, in LOD, the information is stored ina two-dimensional array, but not a traditional chain structure. Most triangles whichare not in the camera’s angle of view will be deleted before API, which will greatlyincrease the speed of applying colors of a drawing. While in other section that havemuch higher requirement towards the hardware, such as Shader technology that cansimulate the real environment will adopt the popular Shader3.0version. We should tryhard to realize the effect of simulation based on ensuring the efficiency. If the CPU of this program does not match with Shader3.0, we can use the CPU to make a softsimulation. But the efficiency will have a loss.The most important things in this thesis are LOD and the simulation of realenvironment. I use the technology related with viewpoint and the extent oftopographical fluctuation to decide the detail of the topography. Each time when weapply colors to a drawing, we will update the topography net dynamically, and we justcolor the point we need. Therefore, the topography net is not regular. The father weare away from the observer, the less the detail is; on the other hand, the much coarserthe land is, the more detail we will have. The same as the other LOD, we just chooseone point recursively till we reach the extent we need. This kind of separation relayson the size of the point, the movement degree of topography, and the distancebetween observer and point. We should figure out the movement degree before handin order to improve the speed.This thesis adopts HLSL language of Microsoft to realize the simulation of realenvironment. We do not use CG language of Nvidia Company. This is because weconsider that HLSL belongs to a technological standard in this trade, while CGlanguage is much like a industrial standard. But when it comes to the practice, thedifference between is not very great. Considering the conveniences of coding anddebugging, this paper adopts FX Composer2.5of Nvidia Company as the developingtoll of Shader.The purpose of this thesis is to realize LOD and Shader, other problems such asapex order, coloring of Shader and low efficiency of timely illumination still exist, sowe just have a simply try on these problems. Meanwhile, the function of dynamicalreading of model and timely edition will be realized, so as to improve the applicationscope of this software.