International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences, Vol XXXV, Part B3. Istanbul 2004
e |
Figure 19 The chosen area in Tsim Sha Tsui
Figure 20 An overview of the extended TIN model
Figure 22 The cross-harbour tunnel
6. Future Developments and Conclusion
The original way of building and extending TIN model without
breaking continuity has been shown. With CAD-type Euler
Operators, the TIN model is built and extended with buildings,
holes and bridges. The extended TIN model is based on the
simple Quad-Edge structure, which takes only a few lines of
program code to implement. The preserved topological
connectivity can serve as a basis for further development,
including neighbour analysis, flow modelling and network
analysis etc.
This sample using Hong Kong data seems to be a good start. In
the future, we hope to include different kinds of data source, for
example, laser images (LIDAR) and aerial photos. Existing
filtering algorithms may help to categorize the features into
different levels of detail.
Reference:
Baumgart, B.G. (1972) Winged Edge Polyhedron
Representation (Stanford Artificial Intelligence Report No. CS-
320, Stanford University Computer Science Department).
Baumgart, B.G. (1975) A Polyhedron Representation for
Computer Vision, American Federation of Information
Processing Societies (AFIPS), The National Computer
Conference, vol. 44, 19-22 May, 1975, AFIPS Press, Anaheim,
CA, USA, pp. 589-596.
Braid, I.C., Hillyard, R.C. & Stroud, L.A. (1978) Stepwise
construction of polyhedra in geometric modelling, in: K.W.
Brodlie (Ed) Mathematical Methods in Computer Graphics and
Design (Leicester, A Subsidiary of Harcourt Brace Jovanovich).
ESRI (Environmental Systems Research Institute, Redlands,
California.) ArcView ® www.esri.com
Gold, C.M. (1998) The Quad-Arc Data Structure, 8th
International Symposium on Spatial Data Handling, T.K.
Poiker & N.R. Chrisman (Eds), Vancouver, BC, Canada, pp.
713-724.
Gold, C.M., Charters, T. & Ramsden, J. (1977) Automated
Contour Mapping Using Triangular Element Data, Computer
Graphics, vol. 11, 170-175.
Guibas, L. & Stolfi, J. (1985) Primitives for the Manipulation of
General Subdivisions and the Computation of Voronoi
Diagrams, ACM Transactions on Graphics, vol. 4(2), April, pp.
74-123.
Lee, K. (1999). Principles of CAD/ CAM/ CAE Systems (Seoul,
Addison Wesley Longman, Inc), 582p.
Mantyla, M. (1981) Methodological Background of the
Geometric Workbench (Finland, Helsinki University of
Technology, Laboratory of Information Processing Science),
70p.
Tse, R.O.C. & Gold, C.M. (2001) Terrain, Dinosaurs and
Cadastres - Options for Three-Dimension Modelling,
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Lemmen & P. van Oosterom (Eds), Delft, The Netherlands, pp.
243-257.
Tse, R.O.C. & Gold, C.M. (2002) TIN Meets CAD - Extending
the TIN Concept in GIS, Computational Science - ICCS 2002,
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in Computer Science, P.M.A. Sloot, C. J. K. Tan, J. Dongarra &
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van Kreveld, M. (1997) Digital Elevation Models and TIN
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