Morakot Pilouk

Currently, a variety of software is capable of handling a wide range of spatial problems, beginning with approaches for describing spatial objects to quite complex analysis and 3D visualisation. However, an increasing number of applications need more advanced tools for representing and analysing the 3D world. Among all types of systems dealing with spatial information, GIS has proven to be the most sophisticated system that operates with the largest scope of objects (spatial and semantic), relationships and provide means to analyse them. However, what is the status of 3D GIS? It is the aim of this paper to find the answer by analysing both available software and efforts of researchers. An overview of several software packages and 3D case studies performed in Oracle and Microstation is given to provide knowledge about the 3D functionality offered by commercial systems. The most significant achievements in the 3D research area concerning key issues of 3D GIS, i.e. 3D structuring and 3...

A three dimensional (3D) model facilitates the study of the real world objects it represents. A geoinformation system (GIS) should exploit the 3D model in a digital form as a basis for answering questions pertaining to aspects of the real world. With respect to the earth sciences, different kinds of objects of reality can be realized. These objects are components of the reality under study. At the present state-of-the-art different realizations are usually situated in separate systems or subsystems. This separation results in redundancy and uncertainty when different components sharing some common aspects are combined. Relationships between different kinds of objects, or between components of an object, cannot be represented adequately. This thesis aims at the integration of those components sharing some common aspects in one 3D model. This integration brings related components together, minimizes redundancy and uncertainty. Since the model should permit not only the representation ...

Currently, a variety of software is capable of handling a wide range of spatial problems, beginning with approaches for describing spatial objects to quite complex analysis and 3D visualisation. However, an increasing number of applications need more advanced tools for representing and analysing the 3D world. Among all types of systems dealing with spatial information, GIS has proven to be the most sophisticated system that operates with the largest scope of objects (spatial and semantic), relationships and provide means to analyse them. However, what is the status of 3D GIS? It is the aim of this paper to find the answer by analysing both available software and efforts of researchers. An overview of several software packages and 3D case studies performed in Oracle and Microstation is given to provide knowledge about the 3D functionality offered by commercial systems. The most significant achievements in the 3D research area concerning key issues of 3D GIS, i.e. 3D structuring and 3...

We have seen GIS software have evolved from simple to more advanced state as it is but yet able to handle applications that associated to 3D and beyond the third-dimension of real world GIS datasets. One of the main reasons attributed to the complexity of spatial data modeling and topological modeling mechanisms for such datasets and information. In this paper, we describe impediments associated with the 3D spatial data, 3D topological modeling, and discuss the possible solutions. We also highlight our initial research effort in this problem domain towards Web enabled system.

Siyka Zlatanova , Alias Abdul Rahman , Morakot Pilouk 3 1 GIS Technology Section, Delft University of Technology, Thijsseweg 11, 2629JA, Delft, The Netherlands. s.zlatanova@citg.tudelft.nl 2 Department of Geoinformatics, Universiti Teknologi Malaysia, 81310 UTM Skudai, Johor, Malaysia. alias@fksg.utm.my 3 Environmental System Research Institute (ESRI), 380 New York Street, Redlands, California, USA. mpilouk@esri.com

Currently, variety of software is already capable of handling a wide range of spatial problems, beginning with approaches for describing spatial objects to quite complex analysis and 3D visualisation. However, increasing number of applications need more advanced tools for representing and analysing the 3D world. Among all types of systems dealing with spatial information, GIS has proven to be the most sophisticated system that operates with the largest scope of objects (spatial and semantic), relationships and provide means to analyse them. However, what is the status of the 3D GIS? It is the aim of this paper to find the answer by analysing both software available and efforts of researchers. An overview of several commercial systems and a 3D case study performed in Oracle and Microstation provides knowledge about the 3D functionality offered by commercial systems. The most significant achievements in the 3D research area concerning key issues of 3D GIS, i.e. 3D structuring and 3D topology portray the current research status. At the end, the paper addresses some of the issues and problems involved in developing such a system and recommends directions for further research. The scope of the paper is limited to 3D GIS systems and research in vector domain. Problems of subsurface applications are excluded as well.

This paper presents analyses of different methods of postprocessing lines that have resulted from the raster-to-vector conversion of black and white line drawing. Special attention was paid to the borders of connected components of maps. These methods are implemented with compression and smoothing algorithms. Smoothing algorithms can enhance accuracy, so using both smoothing and compression algorithms in succession gives a more accurate result than using only a compression algorithm. The paper also shows that a map in vector format may require more memory than a map in raster format. The Appendix contains a detailed description of the new smoothing method (continuous local weighted averaging) suggested by the authors.

The interest in 3D GIS increases due to developments in technology and necessity of users to cope with more complex tasks. Questions related to data acquisition, data storage, data analysis and data visualization are topics for investigations. A key issue on the way of building a 3D model, is an adequate data structure capable to respond to various user queries. The paper elaborates on problems related to 3D model construction for buildings from aerial images, using manual stereo digitizing. The approach relies on a data model based on the 3D Formal Data Structure, which supports 3D topology. The emphasis of the presented work is on an automatic data structuring. The outcomes from the implementation work show that topology facilitates the process of both data acquisition and data visualization.

We have seen GIS software have evolved from simple to more advanced state as it is but yet able to handle applications that associated to 3D and beyond the third-dimension of real world GIS datasets. One of the main reasons attributed to the complexity of spatial data modeling and topological modeling mechanisms for such datasets and information. In this paper, we describe impediments associated with the 3D spatial data, 3D topological modeling, and discuss the possible solutions. We also highlight our initial research effort in this problem domain towards Web enabled system.

In a related paper (Kufoniyi and Pilouk, 1994), a vector data model which integrates multitheme and relief geoinformation was proposed. Here, we present the translation of the model into a prototype relational database structure. We then show an example of the implementation of this structure to create an integrated relief/soil/land use database.

In a related paper (Kufoniyi and Pilouk, 1994), a vector data model which integrates multitheme and relief geoinformation was proposed. Here, we present the translation of the model into a prototype relational database structure. We then show an example of the implementation of this structure to create an integrated relief/soil/land use database.