Generalization Building Model Using CityGML

Oriented Literature Review

Digital Photogrammetry

Martin Deikom

Muhammad Irsyadi Firdaus1

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LiteratureReview

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The main purpose

Generalization of 3D buildings within CityGML For Disaster and

Emergency Management

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Introduction (1) The benefits of 3D Geo-information one of them isfor disaster and emergencymanagement

Open Geospatial Consortium standard, isbeing used to model and representbuildings in different LoDs (LoD0–LoD4),but it does not provide methods togenerate different LoDs automatically4

Introduction (2)

• Generalization based on CityGML specifications

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Methodology

A generalization workflow presented in thisFigure is composed of six steps as thefollowing:(1) derivation of coarse LoDs;(2) projection of outlier of building models;(3) Simplification of segments of the ground

plans extracted from the outlier ofbuildings;

(4) aggregation; and(5) reconstruction of simplified segments of

wall elements. Subsequently, generalizedbuildings are visualized offline. A briefsummary of these steps are given below.

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Simplification of the 2D ground plan

Simplification of offset taking length of neighboringedges into account: original edges of offset (a),extension of the larger edge and identification ofshortest edge (b), and final result of simplificationprocess (c).

Simplification of a segment with a sharpcorner: Original corner formed by two largeedges (a), creation of a triangle with centerpoint (b), and simplified corner (c).

Removal of sharp corner: original shape of corner(a), reduction of longer edges (b), and the result ofthe removal of newly formed smaller edges (c).

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Results

a. original building b. simplified models c. aggregated models

Aggregation of simplified models

3D building models of a portion of Putrajaya, Malaysia, visualized in LandXplorer CityGML Viewer 2009.

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Implementation

Generalization of 3D building

models was implemented in a

C++ application. The platform,

Microsoft Visual Studios 2008,

runs on a PC Pentium (R)

Dual-Core CPU 2.10 GHz, 2.00

GB RAM, and Microsoft

Windows 2007.

Geo-information Requirements Analysis for Industrial Fire Disaster

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This Table is involves the 3D geo-information

requirements of the phases of mitigation, preparation,

response and recovery for industrial fire disaster

management.

Building, transportation, protected sites, energy

resources, production and industrial facilities, and

population distribution and demography feature

types are required with their LOD2-4 information.

That is to say, these data sets are essential for 3D

geo-information to manage industrial fire disaster.

CONCLUSIONS

• We can generate 3D building model using framework of CityGML

• We argue that 3D geo-information that provide advancedvisualisation, analysis and interaction to the actors involved in DEMhave the potential to improve the DEM processes.

• 3D geo-information can resolve many perception problems andimprove the activity management

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Thank you for your attention

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