Validation and Inference of Geometrical Relationships in IFC

The Industry Foundation Classes are a prevalent open standard to exchange Building Information Models. In such a model, geometric representations are provided for individual building elements along with semantic information, including a significant amount of properties related togeometry and explicit topological relationships. These...

Towards an integration of GIS and BIM data: What are the geometric and topological issues?

Geographic information and building information modelling both model buildings and infrastructure, but the way in which they are modelled is usually complimentary and BIM-GIS integration is widely considered as a way forward for both domains. For one, more detailed BIM data can feed more general GIS data and GIS data can provide the context...

Defining simple nD operations based on prismatic nD objects

An alternative to the traditional approaches to model separately 2D/3D space, time, scale and other parametrisable characteristics in GIS lies in the higher-dimensional modelling of geographic information, in which a chosen set of non-spatial characteristics, e.g. time and scale, are modelled as extra geometric dimensions perpendicular to the...

Storing a 3D city model, its levels of detail and the correspondences between objects as a 4D combinatorial map

3D city models of the same region at multiple LODs are encumbered by the lack of links between corresponding objects across LODs. In practice, this causes inconsistency during updates and maintenance problems. A radical solution to this problem is to model the LOD of a model as a dimension in the geometric sense, such that a set of connected...

Sessie 5: Validation and Repair of 2D & 3D Data

Constructing an n-dimensional cell complex from a soup of (n-1)-dimensional faces

There is substantial value in the use of higher-dimensional (>3D) digital objects in GIS that are built from complex real-world data. This use is however hampered by the difficulty of constructing such objects. In this paper, we present a dimension independent algorithm to build an n-dimensional cellular complex with linear geometries from its...

Modelling Higher Dimensional Data for GIS Using Generalised Maps

Real-world phenomena have traditionally been modelled in 2D/3D GIS. However, powerful insights can be gained by integrating additional non-spatial dimensions, such as time and scale. While this integration to form higher-dimensional objects is theoretically sound, its implementation is problematic since the data models used in GIS are not...

Manipulating higher dimensional spatial information

Real-world phenomena have traditionally been modelled in a GIS in two and three dimensions. However, powerful insights can be gained by the integration of additional non-spatial dimensions, such as time and scale, in a higher dimensional spatial model. While this theory is conceptually sound, there is a lack of understanding of its consequences...

Integrating Scale and Space in 3D City Models

This paper presents the problem of the current separate treatment of levels of detail in city models. We propose a solution, detail the main principles, and present our initial results on the approach. We conclude with work in progress and explain the benefits of our approach.

5D Modelling - applications and advantages

As explained in van Oosterom & Stoter (2012), the nD modeling approach allows us to include different aspects of geo-information in spatial modeling at a fundamental level, i.e. by treating these aspects as additional (geometric) dimensions. This paper explains how nD data models and data structures may solve the issues of redundancy and...

Automatically repairing invalid polygons with a constrained triangulation

Although the validation of single polygons has received considerable attention, the automatic repair of invalid polygons has not. Automated repair methods can be considered as interpreting ambiguous or ill-defined polygons and giving a coherent and clearly defined output. At this moment, automatic tools are not satisfactory and repairing is thus...

Edge-matching polygons with a constrained traingulation

While the edge-matching problem is usually tackled by snapping geometries within a certain threshold, we argue in this paper that this method is error-prone and often leads to geometries that are invalid. We present a novel edge-matching algorithm for polygons where vertices are not moved (no snapping is involved); instead gaps and overlaps...