Technical science

Ph.D. Salykova O.S.

Kostanai state University. A.Baitursynov

Сreation of models of objects for three-dimensional GIS

Geographic information systems are dynamically developing technology, used in various areas, including tourism. There are many ways to create three-dimensional maps of cities, but not all of these methods allow you to create quickly and qualitatively three-dimensional maps and faithfully display information about objects. The study considered the most appropriate means to create three-dimensional models of objects GIS. Advantage use of GIS is the ability to calculate and pave маршрут.In are currently many three-dimensional maps of cities around the world, including in Kazakhstan. The city of Kostanay does not exist analogue of three-dimensional GIS maps for maintenance disabled.Технология three-dimensional laser scanning solves problems related to the reconstruction, renovation and engineering, as well as the construction area objects with dense buildings and with plenty of on-ground communications. Processing three-dimensional data allows to receive high-quality topographical plans and accurate digital модели.Создание three-dimensional models of cities is becoming increasingly popular pastime of many GIS specialists. More and more talk about the three-dimensional geographic information systems. Tasks that will address such systems, it is still unclear, however, three-dimensional models of cities have been created for more than a ten лет.Существует several strategies for modeling of three-dimensional objects: Manual creation of the models in the programmes of the three-dimensional modeling, Fully automatic generation of 3D models, Semi-automatic creation of 3D models. For modeling of three-dimensional objects were selected manual and semi-automatic methods. Objects for three-dimensional GIS «Accessible city» has become a social infrastructure, aiming to raise the level of accessibility for people with disabilities and so-called low-mobile groups of population (elderly persons, pregnant women, parents with prams etc). The number of objects selected, entered the building, the Parking and the ways of approaches to assess availability for MH. When modeling in Autodesk 3DStudio MAX GIS maps «Accessible city» were only use simple geometric shapes, Boolean operations, modifiers change the shape of object. Design environmental object or structure of different types includes a few features. The existing objects, which are located in the urban environment, which you must keep intact, should scan three-dimensional scanner and handle received a cloud of points for obtaining highly realistic model. Objects reflecting the design concept of the project, are non-existent, invented by the need to design systems of three-dimensional modeling and then optimize. For objects which are subject to reconstruction or partial restoration, during the design of various forms from simple geometric volumes of plastic forms, you must use the manual method of modeling in packages of three-dimensional graphics. Existing objects are subject to scanning, and the candidate may present the modelling which should be optimized to build a 3D model of the object in GIS. Manual the creation of the models in the programmes of the three-dimensional modeling is the most time-consuming way. A model of a building is created in programs such as AutoCAD, ArchiCAD, ArcGIS+3DAnalyst, 3ds Max or Google SketchUp. Modeling of geometry and texturing models is carried out manually. To simplify the process of city development are allocated sets of typical buildings. Models are created for each type of buildings and then multiplying the correct number of times when placed on a map. To accelerate the process of three-dimensional objects are often produced by the method of extrusion of buildings by means of the plan. The height to which the squeezed out every building of the attribute containing the number of floors. Texturing is usually performed by ground photographs and images from the library of textures. This method of creating 3D models of cities, is the oldest and well изученным. The following step was optimized manually created models. In the package Autodesk 3D Studio MAX using inline modifiers Optimize and MultiRes. Both modifier are (that is - if they were removed from the modifier stack is completely restored the initial geometry of the object), both allow you to achieve good results. Modifiers can be applied on a group of objects. Optimize more towards work with faces and edges, and MultiRes to work with the vertices. When working modifier MultiRes easier to handle and more effective. Consider the received the results of optimization models manually: use the modifier Optimize the number of polygons in test models have succeeded in reducing the average on 60%. Weight models decreased 2-3 times. If further changes to the settings began to change the geometry of building.С the modifier MultiRes number of polygons in test models managed to reduce by 80% without violations of the geometry. But time costs increased.Так was made automatic optimization models obtained with the help of Autodesk 3DStudio MAX. Used plugin Polygon Cruncher, which uses an exclusive algorithm that, given the disparate results - the number of polygons decreased to 92%, but significantly disrupt the geometry of some of the created models and they partially displayed incorrectly in ГИС.Следующим step was conducted comparative analysis of the two methods of modeling of three-dimensional objects in three-dimensional laser scanning and modeling object manually using the 3D Studio MAX.