Therefore, building a 3D virtual city model based on a unified 3D database of content and structure will ensure urban planning and management to take a new step in the construction path
Trang 1MINISTRY OF EDUCATION AND TRAINING
UNIVERSITY OF MINING AND GEOLOGY
MAI VAN SY
RESEARCH ON BUILDING A VIRTUAL CITY MODEL
FOR URBAN PLANNING
SUMMARY OF DOCTOR THESIS
Ha noi, 2019
Trang 2The work was completed at: Department of Cartography, Faculty of Geodesy - Map and Land Management, University of Mining - Geology
Science instructor:
Associate Professor / Doctor Nguyen Truong Xuan
Reviewer 1: Associate Professor / Doctor Tran Dinh Tri
Reviewer 2: Doctor Nguyen Phi Son
Reviewer 3: Associate Professor / Doctor Pham Viet Hoa
The dissertation will be presented and reviewed before the Assessment Council of University-level thesis at the University of Mining and Geology at hours on month year 2019
The thesis can be referred at the library: National Library, Hanoi or the University of Mining and Geology library
Trang 3INTRODUCTION
1 The urgency of the theme
As we know urban planning is the organization and construction of urban space for urban development plans and programs of all levels Urban planning is called urban construction planning Urban construction planning is a technical, social and humanities science, an art of organizing living space for cities and urban areas Urban spaces, technical infrastructure works, urban social infrastructure works need to be planned in accordance with the overall development of socio-economic-environment, security - national defense Urban planning and management must satisfy the total requirements of design, spatial structure planning, ecological, economic and social environments All need a multidimensional environment, namely real 3D space or 4D space (to consider the change over time) The implementation of urban planning and urban design in the 3D environment is a great leap forward in technology to replace the traditional GIS 2D urban planning method, which has great significance for urban managers and designers in the current period
The study and application of 3D map model to represent the land surface only stops at simulating terrain, geography, rendering and assigning simple attributes without building and managing the database (Database) of urban objects in 3D model, there is no standard framework for spatial database and attributes of 3D objects these matters will make the study of 3D model applications in Urban planning in our country not correspond to its meaning and not meet the actual needs Therefore, building a 3D virtual city model based on a unified 3D database of content and structure will ensure urban planning and management to take a new step in the construction path of Smart city (SmartCity) where the 3D virtual city model is set up
as a part of the geospatial data infrastructure (SDI)
In the world, the application of 3D virtual city models in urban planning, design and management, and territorial management has been studied and has become a modern method
In Vietnam, some scientists have begun to study the application of digital mapping, GIS and information technology to build 3D models for some areas However, due to the large workload, many technical problems still encountered and
Trang 43D data standards have not been unified, so far, the development of 3D virtual city models still has faced many issues to be studied In particular, the systematic research and giving the scientific foundation and the process of building 3D virtual city models for urban planning and management need to be implemented
Therefore, the study of scientific basis as well as the application and development of appropriate techniques, tools and methods to build 3D virtual city models for urban planning and management of the thesis's theme is highly necessary, scientific and practical
2 Research objectives
Establishing scientific basis and process of building 3D virtual city model for urban planning and management, proved by experiment in Kien Thuy industrial and urban area, Hai Phong city
3 Research object
According to the theme research goal, the object of study is 3D virtual city model
4 Research Methodology
method of synthesizing materials: Collecting and researching topics already
studied at home and abroad, on the Internet, books, newspapers and magazines related
to 3D models and urban planning Thereby, assess, analyze, classify documents by origin, type, time, author, language into the types of main documents, reference documents, legal documents, and selectively inherit the results which have been studied
Modeling method: Method of map modeling, image modeling, GIS modeling,
structure modeling for digital data
GIS method: Serving database construction and geospatial analysis
Informatics method: Serving the development of application modules
Method of model presentation: Denotation method by digital map, Denotation
method by static, dynamic 3D model
Experimental method: Conducting experiments in Kien Thuy industrial and
urban area, Hai Phong city to prove the research results of the thesis
Expert method: Through workshops, suggestions, getting ideas from experts,
scientists in the field of urban planning, in the field of map surveying and information
Trang 5of intelligent city data model SmartCity
6 New points of the topic
- Proposing 3D virtual city database including content, data structure, detailed level to apply in urban planning and management in our country
- Proposing appropriate technology process in building and exploiting 3D virtual city model for urban planning and management
7 Protection of Arguments
Point 1: The proposed 3D virtual city construction database is fully responsive
to perspective presentation, providing creative and intuitive urban spatial information, ensure analysis and support decision making in urban planning and management
Point 2: The proposed technological process is in line with the requirements of
building a 3D virtual city for urban planning and management
8 Document base of the thesis
The thesis is built on the basis: Systematically summarize the scientific basis to build 3D virtual city model for urban planning and management and create a premise for building and developing SmartCity smart city data models; articles and scientific research works of domestic and foreign authors published in specialized journals
9 The volume and structure of the thesis
The thesis consists of the introduction, 3 chapters, conclusions,
Trang 6recommendations and references The entire content of the thesis is presented in 133 pages of A4 paper, including 6 tables and 70 figures
Trang 7CHAPTER 1 OVERVIEW OF RESEARCH ISSUES
1.1 Overview of urban planning and management in our country
1.1.1 Overview of spatial planning and urban planning
The demand for economic development in the context of competition and conflicts for space exploitation and use in Vietnam is increasing Therefore, the application of space planning has become an urgent practical need in general and unified state management for Vietnam in the coming time
It can be said that space planning and spatial integrated management are still new issues for not only managers and policy makers, but also for scientists and planners in Vietnam
There are some planning levels as follows:
- General planning
- Zoning planning
- Detailed planning
1.1.2 Requirements of urban planning
1.1.2.1 Content of urban planning
Urban planning is the organization of living space for people in cities and urban areas, the art of arrangement and organizing functional spaces, establishing architectural forms in urban areas on the basis of investigating, analyzing, evaluating, forecasting, estimating the development, characteristics, roles and position in the relationship of regions, needs and resources of urban development, to concretize development strategies and policies and minimize harmful impacts arising in the process of urbanization, making the most of all resources and towards sustainable development It is possible to see the indispensable importance of map products (2D)
in planning in general and urban planning in particular The quality, method and denotation of urban space on the map model have great significance in the content of urban planning schemes This is a highly technical issue with a combination of planners and map makers, to provide competent authorities in a plan review and at the same time for agencies, organizations and individuals in the implementation of
Trang 8planning plans in the most effective way
1.1.2.2 Functions of some types of maps in planning projects
Topographic maps for the elaboration of urban planning schemes built and issued by state management agencies on maps or by surveying and measuring agencies, ensuring the prescribed quality and technical requirements about measuring map product The information and data of topographic maps must meet the requirements for urban planning in conformity with each type of urban planning scheme In case the topographic map is not suitable for the current situation at the time
of planning, the supplemental survey and measurement and adjustment are carried out
1.1.3 Current situation of urban planning and urban management in our country
From the problems raised and the requirements of urban planning practices, the trend of applying 3D technology to spatial modeling has brought not only for many sectors but also for urban construction planning a special importance
In the past, urban design, planning and management were often carried out on the basis of 2D maps and in addition GIS 2D These types of maps do not represent three-dimensional space of urban areas and are difficult to understand if we are not professionals With the development of information technology and related graphics technologies, advanced 3D technology through the use of 3D virtual city models has overcome the disadvantages of 2D technology The 3D virtual city models allow planners and the public to understand complex urban spaces and understand the impact
of future developments Such 3D models not only help urban planners perform advanced analysis, planning and decision making, but also help to strengthen transparency in planning by effectively providing planning information to community with the community Currently, 3D technology in general, 3D virtual city model in particular is being researched and widely applied in urban design, planning and management in developed countries and initially in our country This once again confirms the urgency of the thesis topic
1.2 Overview of the situation of 3D model application research in urban planning and management in the world
Currently, in the world, 3D models applied in urban planning and management have been interested and studied in many countries such as Australia, Japan, Germany,
Trang 9England, China, Taiwan, etc [84] , [69], [58], [43], [59] Right from the beginning of the history of cartography development, mapmakers discovered many methods of modeling the earth's surface on the map plane With 3D models, cartographers have modeled the territorial surface visually and vividly, making the process of territorial awareness faster and more intuitively 3D models have been used in many different areas such as hydrology, transport, planning, military, [43], [44], [68] In particular, the idea of applying 3D technology in planning work was introduced by Saarinen in the first half of the 20th century [40] However, only when information technology developed, was the realization of Saarinen's idea possible [36], [83]
1.3 Overview of research situation in Vietnam
In Vietnam, in the last few years, 3D GIS and three-dimensional maps have also been studied It is possible to list here some typical studies such as: the works of
"representation of three-dimensional map and application" [16] The study focused on three-dimensional map representation methods, thereby showing that the network of irregular triangles (TIN) is suitable for representing three-dimensional maps This study focused on the basic concepts, mathematical foundations of three-dimensional topographic maps, thereby, propose to test methods of constructing and representing three-dimensional topographic maps based on technology ArcGIS of ESRI (USA) In
2008, in Hanoi, the Ministry of Construction organized a seminar on "Seminar on application of geographic information systems (GIS) in urban development", which emphasized the important role and applicability of 3D GIS for the city planning and architecture support as well as traffic problems Currently, in our country, many new technologies have been applied to collect three-dimensional spatial data such as sweeping terrain using laser (LiDAR), stereoscopic measurement and drawing, orthogonal radar, etc These data are very good input for modeling three-dimensional maps, but currently these data are newly stored as a text file (text) set of xyz coordinates, regular grid pattern (grid) The natural resources and environment industry is in need of specific research to apply to observable data objects to build and manage three-dimensional maps
1.4 Research orientation of the thesis topic
Through researching and studying the technology development process and research projects in the world and in our country, we realize that: Some developed
Trang 10countries in the world have initially researched and successfully applied 3D virtual city models in urban planning and management The content of their research focuses on three issues: techniques of building 3D virtual city models, developing tools (hardware and software) and building information systems based on virtual city models and link with e-government model
Therefore, with the wish to contribute to the early application of 3D virtual city model in urban planning and management in our country, the researcher has oriented the research as follows: On the basis of reference and inheriting a number of research achievements in the world and some initial research results in our country, will systematically study the scientific basis of technology, including a list of content and structure, the detailed level of 3D virtual city model, proposing the process of building 3D virtual city model, and studying the experimental application of building 3D model
of Kien Thuy industrial urban area with area about 912,83ha in Hai Phong City to verify
Conclusion chapter 1
So far, the view of urban planning and management has changed significantly Although in the process of urban planning and management in the past, only a few organizations and experts work in their own fields, but the current planning and management are increasingly concerned by participation and cooperation among different groups of stakeholders and by closer integration in the areas of expertise
There have been many special scientific research projects, not building 3D virtual city model based on 3D database for the orientation of spatial planning, the concept of virtual city model in the form of New space simulation has been approached by a number of authors in a number of research projects, building 3D virtual city model based on 3D database as an approach from 2D GIS to 3D GIS receives very little research in Vietnam
On the basis of reference and inheritance of some research achievements in the world and some initial research results in our country, there will be a systematic study
of the scientific basis of technology, which proposes table of content, structure, detailed level of 3D virtual city model, the process of building 3D virtual city model
Trang 11CHAPTER 2 SCIENTIFIC BASIS FOR BUILDING A 3D VIRTUAL CITY FOR URBAN PLANNING AND MANAGEMENT 2.1 3D virtual city
Concept of 3D virtual city
3D virtual city model (3D geovirtual abbreviated as GeoVEs) is understood to
be the digital representation of real cities, can see the city at any point and explore interaction by users on the computer based on geospatial data This definition emphasizes three important aspects:
1 3D virtual city model provides an interactive media, a virtual space, allowing users to explore truly miniature urban environment in modeling
2 3D virtual city model consists of three basic components: Geospatial data, visual systems that transform data into interactive 3D models, software and computer hardware
3 The 3D virtual city model is geographic space, i.e the real position of any object described in the data model and is displayed as a 3D object
2.2 Content Spatial data of 3D city model
2.2.1 3D geographic background group data
* Digital Elevation Model (DEM)
* Digital Terrain Model (DTM)
* Digital surface model (Digital Surface Model - DSM)
* Geographic background data from large scale topographic maps
* Materials without photos
* Ground image data
2.2.2 Geological group data in urban space
2.2.2.1 Groups of geological objects
Objects located right on the road surface topography such as rivers, streams, roads, points like control points can be described by 2D or 3D data For 3D data they can be represented independently and accurately in their 3D environment, regardless
of the terrain surface data as their background
Trang 12On 3D maps, details of urban areas, houses and blocks are a group of objects which are very interested in how to express This group is quite diverse in geometric structure They can be detailed in real 3D models, each with X, Y, H values or generalized at different levels depending on the level of detail shown
2.2.2.2 Building houses and construction works on the basis of 3D terrain
On the 3D terrain map, houses can be represented by foot contour polygon with house height and fire resistance properties This height is obtained from the results of the last-echo lidar data as mentioned above At first, the home polygon layer is overlaid on the DTM face with the Base height tool
2.2.2.3 Show other objects on the map
- Hydrology and related objects
- Traffic and related objects
- Economic and social cultural objects
- Power lines and information lines
- Soil shape and soil
- Plants:
- Note:
2.2.3 Integration from other data sources
2.2.3.1 Data integration of areas to be protected
Data on nature reserves or other protected areas are stored as geographic vector data Attribute tables contain information about the protection status, the name of the protected area, the date specified, the legal basis for the assignment Figure 2.2 shows three methods used to visualize data on protected areas in a 3D virtual city model
2.2.3.2 Integrated water areas
Land use data from digital cadastral maps has been used to select water area and combine them into CityGML Water Objects which are integrated into 3D virtual city models Therefore, the selected features have been converted and written to CityGML file
2.2.3.3 Integrating plans from urban planning
Several planning processes have taken place and are still ongoing in the area we study So far, three different types of plans have been tested: master plans,
Trang 13development plans and construction plans
2.2.3.4 Integrated master plans
The main issues in the planning process are the concept of height and construction density of planning proposals, master planning and planning versions which have been continuously integrated into the 3D Land Information System to provide visual simulations during the planning process
Figure 2.2: Integration method
for geographic vector data
Figure 2.3: Extrusion-based modeling method used to represent overall diagrams through Block models and terrain surface structures
Figure 2.4: 3D modeling approach to create
planning representations as 3D models
Figure 2.5: Illustrate modeling methods
based on CityGML
2.2.3.5 Integrated planning diagrams
The second type of planning to be tested is planning schemes Planning schemes are legally binding planning documents, which define future land use as well
as construction density and construction objects
2.2.3.6 Integrated construction projects
It is necessary to edit topology data and create a data set of building block feature They are prepared by adding attributes that keep height information and export
to SketchUp The main plot plans and drawings, which must be prepared for construction permission, will be used as an alternative to the 3D model
2.2.3.7 Integrate more information through attributes, impacts and annotations
The methods presented so far focus on integrating visual representations of geodata and planning into 3D city models In many cases, these visual representations