PDF of SGA Pattern Image: Image:USOcore3.pdf

To answer the modern, interdisciplinary questions asked within the Building domain, industry tools and data standards need to become far more interoperable in order to be able to provide a full and accurate set of analysis to engineers and designers. To provide this full picture from which to make decisions, we needed a way to resolve the spatial data that tools provide in order to synthesize it together. In addition to missing, incorrect, and inconsistent information, there is also the challenge of not being able to use existing spatial patterns to capture the full granularity or specificity of the geospatial descriptions required to capture full and dynamic geometric contexts.

The Spatial Graph Adapter (SGA) pattern provides us a way to extend the simple identification of geometries and simultaneously assign further descriptions and self-context as well as contextual and relational references to other spatial objects in or surrounding the original entity. For example, not only can we use existing notions say that one surface is adjacent to another, but we have a way to say exactly what type of adjacency and to what extent it is adjacent (more examples in accompanying paper). The SGA has also been implemented for several building industry schemas and our further research is in bringing this and other patterns into full use in a Linked Data Platform (ongoing).

http://ontologydesignpatterns.org/wiki/Community:Building_and_Construction

• 1. What spaces is this damaged structural beam a part of (without needing to iterate through every existing spatial component or coordinate set)?

2. Exactly how much of this structural element is exposed and to what spaces?

3. What are all of the spatial elements in this graph that contain void spaces (air spaces in assemblies that could be susceptible to damage)?

4. What thermal or occupancy zones is this assembly associated with (these may or may not have to do with adjacency or locality)?

5. What sets of columns are responsible for supporting floors X and Y?

Even if we use a common definition for adjacency, such as where two objects would be touching could be considered adjacent, this fails when we want to know, say what columns or walls are adjacent to a space. It is true that they may be touching some building geometries, but what about the cases where you would have adjacent columns, but they are touching only the open air that define that side of a space (not touching but still on that visual or schema induced boundary)? The SGA pattern allows us to extract this type of information and add it as Attributes or ContextualizedRelations to other objects, solving this issue by being able to, for example, group building elements even as what may seem arbitrary in isolated examples. Schemas produce a wide array of these situations, and even more when we start to translate between them.

SGA Pattern

With the capabilities the SGA pattern provides, it has been found to be useful and as been implemented for IFC, GBXML, and CityGML is currently in progress. Once this mapping was produced and captured via this pattern, further work was possible and completed in the form of View helper files and all of this is being worked into an operational Linked Data Platform to further enhance open data exchange.

Our work was inspired by ideas from Spatial Information Theory, biomedical research for the Semanticscience Integrated Ontology (SIO), Mereotopology, and geospatial data efforts via the Open Geospatial Consortium (OGC), although these are not the only works regarding spatial descriptions.