Method And Technology Of The 3D Modeling Method Of Ancient City Based On Rules

With the concept of digital earth, digital city has been known by most people, the study of 3D modeling method has been developed rapidly in recent years. Using 3D modeling method based on rules to make 3D model is more and more people’s choice. With every city gets it’s own local history museums or exhibition buildings, the demand about digital sand table of the ancient city is also increasing.Ancient Chinese architecture compared to modern architecture and the characteristics of Western architecture has three aspects, the uniqueness of the buildings, Etiquette uniqueness, style styling unique. As the ancient city has such characteristics, the rules of building the ancient city 3D model are different to the rules of the modern city. This article uses a rule-based three-dimensional modeling method, takes the ancient city as the research object, makes sure three-dimensional modeling to explore the ancient city of methods and processes. And the main contents are as follows:①Determine using a variety of data to recovery the ancient city building location process and restore the city of Lanzhou in Qing Dynasty location and layout of the city by collecting data.By collecting the existing site points, rare books, remote sensing images and other data, it can be done by using GIS technology to recovery position and location of the ancient city during the city building. Complianced with the "from known to unknown, first accurate then presumably, from point to line to polygen" principle, use of remote sensing images to correct the map of the city of Lanzhou Chi Qing Dynasty schematic Lanzhou city. Using roads, sites and other points through modern mapping, GPS positioning data, the schematic drawing can be accurately corrected, or changed. Finally, the relationship between surface features and location near Lot reasonable inference other block diagram, resulting in a relatively precise location of the ancient city and the city building.②According to the characteristics of ancient architecture, study the based on rules method of three-dimensional modeling of the ancient city.Image modeling and rendering methods, constructive solid geometry method, based on the man-machine interactive method, based on the shape of the syntax and semantic rules method, these four methods of three-dimensional modeling were compared, from which to select the appropriate modeling approach, using human-computer interactive methods and shape of the syntax and semantic rules based on a combination of methods. Using rules based modeling methods overall layout modeling and 3D modeling based on the shape of ancient city ancient building method syntax and semantic rules. Construction details of the use of man-machine interactive method to compensate for part of the building based on the shape of the syntax and semantic rules shortcomings of the details of the method.③Determine using a complete three-dimensional modeling of the ancient city of statements based on the shape and semantic rules and methods of human-computer interaction method combines process flow.Determine the data preprocessing, model layouts of buildings, single building modeling, building modeling detail, this basic 3D modeling ancient city flow sequence. So that the model can build fast, complete, and orderly manner. Rearranging the information, learn ancient architecture distribution layout and structure of the ancient buildings. Combining the characteristics of the ancient buildings, located from buildings, structures and building single detail three, layers, and gradually refined 3D models. Write rules file and a reasonable set of parameters such that the model has an adjustable resistance, which can adjust the parameter values so that the model is consistent with the structure of ancient Chinese architecture style.This article that use a variety of data to determine the location and spatial layout of the ancient city’s main method is whether the data collected in detail and whether the position can be restored by modern GIS technology. The use of 3D shape modeling method statements and semantic rules and methods of human-computer interaction method for three-dimensional modeling of the ancient city is a simple, low-cost, efficient way. According to the characteristics of the ancient city, from modeling to the layout of buildings single building modeling, to model the details of the building, constructed three-dimensional model of the stepwise refinement, sophistication model has gradually increased. In general, this method can reduce labor costs and improve modeling accuracy.