Proceedings, XXth congress: Proceedings, XXth congress

Altan, M. Orhan

Bibliographic data

Multivolume work

Persistent identifier:: 1663674213

Title:: Proceedings, XXth congress

Sub title:: Istanbul, 12 - 23 July 2004

Year of publication:: 2004

Place of publication:: Istanbul

Publisher of the original:: [Verlag nicht ermittelbar]

Identifier (digital):: 1663674213

Language:: English

Additional Notes:: Erscheinungsdatum des Originals ist aus dem Copyrightjahr ermittelt.; Auch bezeichnet als XXth International Congress for Photogrammetry and Remote Sensing

Editor:: Altan, M. Orhan

Corporations:: International Society for Photogrammetry and Remote Sensing, Congress, 20., 2004, Istanbul; International Society for Photogrammetry and Remote Sensing, Commission Primary Data Acquisition

Adapter:: International Society for Photogrammetry and Remote Sensing, Congress, 20., 2004, Istanbul; International Society for Photogrammetry and Remote Sensing, Commission Primary Data Acquisition

Founder of work:: International Society for Photogrammetry and Remote Sensing, Congress, 20., 2004, Istanbul; International Society for Photogrammetry and Remote Sensing, Commission Primary Data Acquisition

Other corporate:: International Society for Photogrammetry and Remote Sensing, Congress, 20., 2004, Istanbul; International Society for Photogrammetry and Remote Sensing, Commission Primary Data Acquisition

Document type:: Multivolume work

Volume

Persistent identifier:: 166368779X

Title:: Proceedings, XXth congress

Scope:: IV, 226 Seiten

Year of publication:: 2004

Place of publication:: Istanbul

Publisher of the original:: [Verlag nicht ermittelbar]

Identifier (digital):: 166368779X

Illustration:: Illustrationen, Diagramme

Signature of the source:: ZS 312(35,B8)

Language:: English

Additional Notes:: Erscheinungsdatum des Originals ist aus dem Copyrightjahr ermittelt.

Usage licence:: Attribution 4.0 International (CC BY 4.0)

Editor:: Altan, M. Orhan

Corporations:: International Society for Photogrammetry and Remote Sensing, Congress, 20., 2004, Istanbul; International Society for Photogrammetry and Remote Sensing

Adapter:: International Society for Photogrammetry and Remote Sensing, Congress, 20., 2004, Istanbul; International Society for Photogrammetry and Remote Sensing

Founder of work:: International Society for Photogrammetry and Remote Sensing, Congress, 20., 2004, Istanbul; International Society for Photogrammetry and Remote Sensing

Other corporate:: International Society for Photogrammetry and Remote Sensing, Congress, 20., 2004, Istanbul; International Society for Photogrammetry and Remote Sensing

Publisher of the digital copy:: Technische Informationsbibliothek Hannover

Place of publication of the digital copy:: Hannover

Year of publication of the original:: 2019

Document type:: Volume

Collection:: Earth sciences

Chapter

Title:: PHOTOREALISTIC BUILDING MODELING AND VISUALIZATION IN 3-D GEOSPATIAL INFORMATION SYSTEM Yonghak Song, Jie Shan

Document type:: Multivolume work

Structure type:: Chapter

ecision- rate the C VIEW, | ortho- Objects creation ted and these 3- ing with ddition, ponding e model xturing, th other These ance its ion and nportant fect. To realistic nted. nd other adelling. ained by ch, only oofs can porate it as wire- ly GIS ' used in omputer 'epresent such as loundary cts with Iowever, playing n of the odel and the wire explicit ymbol in International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences, Vol XXXV, Part B-YF. Istanbul 2004 the wire frame model stands for the closing vertex of a polygon, based on which the faces for rendering are generated. The surface model is an advanced wire frame model. The object is represented not only by edges but also by surface components called patches, each of which may consist of several polygons. These polygons can be simply represented by vertices and their topology if necessary. The data structure is simple so it can ensure fast rendering. However, as a trade-off, the polygon- based surface modeling may not be adequate to show the curve objects with high fidelity because the number of segments required to compose the curve is increased proportional to the radius of curvature (Foley, et, al, 1993). After comparing both modeling methods, we decide to apply the surface model in this paper. The reasons are its simplicity and good supportability by GIS tools. Also, attribute data can be directly associated to the building object because it consist of polygons. In addition, buildings in GIS are usually not considered as solid objects and are mostly composed of straight edges or boundaries. Therefore, the advantage of the solid model and disadvantage of the surface model are marginal in case of modeling the buildings for visualization applications. (b) Figure 1. Wire Frame model (a) and Surface Model (b) for Geometric Building Model Once the modeling method is selected, we consider its association with the corresponding image textures. In general, 3-D graphic software use the directional projection method for texture mapping so we need to avoid that the patches are overlapped when they are projected on the plane. For this reason, the geometric building model is separated into roof and wall two parts. In our approach the shapefile format of ESRI 17 (Environmental System and Research Institute) is adopted and enhanced for 3-D building modelling and visualization. This file structure consists of a main file, an index file, and a dBASE table. The main file is a direct access, variable-record-length file in which record describes the shape with a list of its vertices. The index file contains the offset of the corresponding main file record and the dBASE table contains the feature attributes. (ESRI White Paper, 1998) The main file supports shape types in 3-D space such as PointZ, MultiPointZ, PolyLineZ, PolygonZ and MultiPatch. Usually the MultiPatch shape is good and suitable for 3-D drawing. However, it is difficult to include various topology and spatial analysis functionalities provided by GIS and to directly link the attribute data to geometric object. Therefore, we choose PolygonZ type and modity it to fit to our objective for building modeling and visualization. This will be addressed in the next sections. The shapefile containing polygons with z-value is created when digitizing a pair of aerial stereo images using the Stereo Analyst of Erdas IMAGINE. The initial data from the Stereo Analyst for the building models contains the 3-D coordinates of roof vertices and z-values of building footprint at the ground level. The coordinates of walls can be automatically generated using such information in shapefile based on the assumption that walls are vertical to ground. Hence, if some parts of building have no vertical relationship with ground foot, they are considered as a roof in terms of model structure even they are walls in real. These geospatial data of vertical walls is added into the roof shapefile. The main file structure of the modified shapefile for building is shown below in Figure 2. In this way, we successfully integrate all building components in to one compact data model, which will benefit the texture mapping and model rendering process in the subsequent steps. Spatial data structure for building model { Double Box //Bounding Box Integer Num parts //Number of parts Integer Num points //Total Number of points Integer Parts //[ndex to first point in part Point Points //Coordinates of points for roof parts Point Points //Coordinates of points for wall parts Double Z Range //Bounding z range Double Z Array //Z Values for roof points Double Z Array //Z Values for wall points Double M Range //Bounding measure range Double M Array //Measures 1 J Figure 2. The Data Structure of Main File for Building Model 3. TEXTURE CREATION For the photorealistic building modeling, each building façade (a planar face, either vertical or not vertical) requires an association to a realistic texture that is possibly composed of a colour image with three bands, or the RGB colour intensities in the simplest case (Gülch, E, 1997). Two different ways are used to acquire and associate the images to building objects, respectively for roof and walls. As mentioned earlier, a building is separated to roof and walls for geometric model and texturing. For roof texture, the ortho-rectified aerial image, created using

Access restriction

Copyright

fullscreen: Proceedings, XXth congress (Part 8)

Multivolume work

Volume

Chapter

Table of contents

Cite and reuse

Volume

Chapter

Image

Image fragment

Citation links

Citation recommendation