Many data exchange standards for 3d spatial data applications exist, ranging from the general Geography Markup Language (GML) underpinning CityGML to specific models for business application domains, such as BuildingS...
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Many data exchange standards for 3d spatial data applications exist, ranging from the general Geography Markup Language (GML) underpinning CityGML to specific models for business application domains, such as BuildingSMART Industry Foundation Classes (BIM/IFC). There are a number of different approaches to modelling 3d objects, and in general the geometry aspects of these can be readily understood in the context of the visualisation needs of different applications. The topology, or relationships between elements of these objects, on the other hand is either not directly supported by such geometry models or implemented in different ways by different standards. We discuss limitations of existing standards for describing topological relationships in particular. In some cases topology information is embedded in geometry objects using identifiers for vertices, edges and faces, but in general there is scope to develop a standardised model for describing alternatives for topology and3d geometry representations. A limited set of such models allows for interoperability via transformations between different representations. The ISO 19107 Spatial Schema provides an adequate conceptual model for these concerns, so we present the argument that a profile of this comprehensive model be defined for the limited set of such representation options required for Smart Cities and other similar applications.
To increase productivity, quality, and safety, heavy industrial construction projects are increasingly adopting prefabrication and modularization techniques. This shift, in turn, has resulted in fabrication shops fabr...
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To increase productivity, quality, and safety, heavy industrial construction projects are increasingly adopting prefabrication and modularization techniques. This shift, in turn, has resulted in fabrication shops fabricating more complex assemblies with tighter tolerances. However, most measurement in these shops is conducted using manual hand measurement tools, which can be costly and is known to cause significant rework due to geometric noncompliance of termination points in particular. Termination points are defined as the coordinate system points where assemblies connect or are constrained. Automated, 3d-scanning measurement and visu-alization systems can potentially be accurate, repeatable, and objective sources of termination point data. In this paper, a new framework for classification and calculation of termination points is presented that is based on automated, 3d-scanning measurement and visualization. The utilization of the framework enables fabrication shops and project owners to adopt effective 3d measurement solutions. To investigate the usefulness of the defined framework, a termination-point-based scan-vs-BIM method is developed for objects with circular cross sections, such as pipe spool assemblies. The method was validated in an industrial-scale experimental study. The study demonstrated that the new framework can be used to develop applications that are more accurate and provide superior visualization to craft workers during fabrication, and thus potentially improve produc-tivity and reduce rework.
This paper presents a research project in The Netherlands in which several SMEs collaborated to create a 3d model of the National spatial planning information. This 2d information system described in the IMRO data sta...
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Cultural Heritage artifacts can often be underestimated for their hidden presence in the landscape. Such problem is particularly large in countries like Italy, where the massive amount of "famous" artifacts ...
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Cultural Heritage artifacts can often be underestimated for their hidden presence in the landscape. Such problem is particularly large in countries like Italy, where the massive amount of "famous" artifacts tends to neglect other presences unless properly exposed, or when the remains are dramatically damaged leaving very few interpretation clues to the visitor. In such cases a virtual presentation of the Cultural Heritage site can be of great help, specially for explaining the evolution of its status, giving sometimes sense to few spare stones. The definition of these digital representations deal with two crucial aspects: on the one hand the possibility of 3d surveying the relics in order to have an accurate geometrical image of the current status of the artifact;on the other hand the presence of historical sources both in form of written text or images, that once properly matched with the current geometrical data, may help to recreate digitally a set of 3d models representing visually the various historical phases (diachronic model), up to the current one. The core of this article is the definition of an integrated methodology that starts from an high-resolution digital survey of the remains of an ancient building anddevelops a coherent virtual reconstruction from different historical sources, suggesting a scalable method suitable to be re-used for generating a 4d (geometry + time) model of the artifact. This approach has been experimented on the "Basilica di San Giovanni in Conca" in Milan, a very significant example for its complex historic evolution that combines evident historic values with an invisible presence inside the city.
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