The International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences. Vol. XXXVII. Part B4. Beijing 2008 
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</xs:extension> 
</xs : comp lexContent> 
</xs:complexType> 
< ! -============================= „> 
Surfaces represent walls, roofs, base closure of real buildings; 
these elements are geometric attributes of _Boundedby class. 
<!— ==========================:=== -_> 
<xs:complexType name="_BoundedbyType" abstract="false"> 
<xs:complexContent> 
<xs:extension base="GIANT3DObjectType"> 
<xs:sequence> 
<xs: element 
type="BuildingsurfacecomponentType" 
maxOccurs="unbounded"/> 
<xs:element 
type="BuildingsurfacecomponentType" 
maxOccurs="unbounded"/> 
<xs:element 
type-'BuildingsurfacecomponentType" 
maxOccurs="unbounded"/> 
</xs:sequence> 
</xs:extension> 
</xs : complexContent> 
</xs : comp lexType> 
<!— ========================== __> 
<xs:element name="Boundedby" type="_BoundedbyType" 
substitutionGroup="GI ANT3 DObj ect"/> 
<!— =====================—-> 
Ground_size, maximumsize, crowning, terrain- 
buildingjntersection, bounded, property lands are further 
geometric attributes of the class (Figure 4). These attributes 
provide useful informations for disaster management, town 
planning, navigational purpose connected to GPS-GIS 
technologies, etc. 
5.EDITING AND BROWSING SOFTWARE 
In order to edit and handle data structured according to the 
GIANT3DModel, two software modules have been realized: the 
first attends to structure the three dimensional urban model, the 
second attends to explore the model. 
5.1 GML3 editor 
The module by which it is possible to structure the model 
provides also to export it in GML3 format (OGC compliant); it 
has been implemented with commercial software (Autocad®) 
that, today, is the most suitable solution for data editing. 
Starting from simple objects in CAD environment and using a 
suitable software application running in a CAD environment, 
geographical objects can be defined both geometrically and 
topologically; attributes can be stored in a relational database, 
so really carrying out a 3D city model. 
Using the editor plugin data can structured based on rules 
belonging to GIANT3DModel; at the end, data can be exported 
in GML3 format, OGC compliant. 
This editor-modeler is an Autocad®® plugin, developed using 
SDK Object ARX: it allows you to assign tag and attributes to 
objects, that are saved in a database. Once the plugin is loaded, 
it opens a toolbox over main window of Autocad®: many tabs 
(like Building, Artefact, Infrastructure, Vegetation, Orography, 
Services, Hydrographical, Building group) with text fields and 
check buttons allow to choose what elements of drawing 
combine to bring about objects and their attributes (Figure 5). 
As an example, information like class, typology, function, 
floors, etc. can be loaded for a building, according to limitations 
and parameters of cartographic model. 
Finally, after that data set has been structured, information can 
be exported using the application schema of the model to write 
a GML3 file. 
This modeler can be used with several version of Autocad®, 
including “Map” versions too. 
Defining application schema, used by the modeller, a constraint 
regarding the use of only straight segments and only flat 
surfaces has been imposed. This constraint considerably 
simplifies three-dimensional triangulation. 
5.2 GML3 Browser 
To explore and query files made by plugin described above, 
representing a three-dimensional model of territorial objects, a 
viewer has been developed. 
name-'Wall" 
minOccurs="3" 
name-'Roof' 
name-'Buildingplug"