Computing and analysing big data on a single computer is a well-known problem. The authors provide insight on a way around this problem through the use of an external memory system for optimised big data management by incorporating the STXXL C++ library into an existing software system. In this paper the authors describe the performance of two different versions of their cloud-based data processing software, one of which incorporates STXXL’s intelligent caching system to automatically page data to-and-from a filesystem on-disk. The experiment compares a software architecture without STXXL, to a new one with STXXL integration, in order to establish what benefits exist for using external memory caching versus in-memory processing. The tested software versions perform computations within the authors’ cloud infrastructure, utilising sample datasets in ASTM E57 Format for the point cloud(s) and IFC STEP Physical File Format (SPFF) for the building information model(s), and the behaviour of these computations are recorded and analysed. The authors’ results show that a robust and performant external memory implementation can increase the affordability and scalability of cloud-based solutions, as the cost of hardware in the cloud is a major expense for maintaining systems of this kind. Results show that while the speed of each individual execution is lowered, a higher level of throughput in a given time period allowed the external memory system to exceed the original software’s overall performance, and enabled greater efficiency when handling analyses.
External Memory Solution for Large-Scale Point Cloud Data Processing. Proceedings of the CitA BIM Gathering
Hyland, N. and O’Keeffe, S
The authors have developed a Scan-vs-BIM validation approach that computes correspondences between reality capture data and Building Information Models (BIMs). The tool utilised for producing correspondences is called AutoCorr and was developed as a key component in the authors’ cyber-physical system known as the BIM & Scan® Platform. The tool’s algorithms automatically detect, highlight, and virtually display differences between an IFC Coordination View in STEP Physical File Format (SPFF) and its corresponding point cloud in E57 format. AutoCorr, when using as-is, as-built, or as-designed BIMs, helps to answer important questions, e.g. “Is what was agreed, what has been built on-site?” and “Is the construction-in-progress going according to the agreed design?”. Furthermore, the tool enables the validation of “as-generated” IFC BIMs created automatically via our AutoGen reconstruction tool, helping to answer the question: “How accurate is the as-generated model according to the point cloud it came from?”. The presented automatic validation approach allows the authors to study the accuracy of traditional and reconstructed BIMs during different phases of the facility life cycle, hence affording possible automated resolutions to discrepancies between the real and virtual worlds.
Validation of As-Is and As-Generated IFC BIMs for Advanced Scan-to-BIM Methods. Proceedings of the CitA BIM Gathering.
O’Keeffe, S., Hyland, N., Dore, C. and Brodie, S
The authors have developed a novel methodology utilising open standards for the reporting and correction of IFC-formatted BIMs during comprehensive dimensional control compliance. The problem being addressed is that as-designed BIMs rarely match exactly what is built on-site. Traditional methods for ensuring the design matches the built environment are very tedious, costly, and time-consuming as project stakeholders must manually navigate through the model to find problems, relying on their subjective judgement. An efficient method to develop accurate as-built and/or as-is BIMs is by comparing point cloud reality capture data against the as-designed BIM to reflect the real-world state of the built environment. The novel methodology presented in this paper uses automatic model reconstruction techniques to create a comparable data model between the as-designed BIM and as-is point cloud, and employs the open standard BIM Collaboration Format (BCF) in the communication and correction of as-designed BIMs to match the as-is state. BCF enables project stakeholders to share comments, notes, and potential issues with one another without the need for exchanging the entire model. Our automated dimensional control compliance solution produces BCF-based reports containing issues recognised as an error/deviation measurement between the as-is state and the as-designed BIM. These deviation reports contain the necessary data to refer stakeholders to the model elements in question through encoded camera viewpoints, supported by major BIM authoring tools, and viewers. The methodology outlined in this paper was validated using real-world scan data and a corresponding BIM.
Automatic Open Standard Reporting for Dimensional Control Compliance. Proceedings of the CitA BIM Gathering.
Hyland, N., O’Keeffe, S., Brodie, S. and Dore, C
The authors developed a cloud-based cyber-physical system known as the BIM & Scan® Platform. This platform facilitates a scalable interface for applications that support verification and validation methodologies in the digitisation of the built environment. These methodologies support, but are not limited to, assuring what was designed is what was built and delivered. The platform operates utilising open standard data formats for real and virtual worlds. This paper emphasises the need for and utilisation of “open” standards and serialisation formats for quality assurance of contracted deliverables, i.e. as-built BIMs and COBie. The paper further demonstrates the BIM & Scan® Platform’s current tools (AutoGen, AutoCorr, and AutoDiff) for automatic generation of ISO 10303-21 formatted IFC MVD files from reality capture data, automatic COBie file verification and quality check (QC) reporting, and using IFC SPFF, BCF, and E57 formats for automatic dimensional control compliance methods and reporting.
The BIM & Scan® Platform: A Cloud-Based Cyber-Physical System for Automated Solutions Utilising Real & Virtual Worlds. Proceedings of the CitA BIM Gathering.
Brodie, S., Hyland, N., Dore, C. and O’Keeffe, S
Two types of technologies that are rapidly (exponentially) impacting the Architecture, Engineering, Construction, and Facilities Management (AEC/FM) industry are: Building Information Modelling (BIM) and 3D imaging technologies. The latter is currently mainly represented by laser scanning, but is being rapidly complemented with photogrammetry (both terrestrial and aerial), ground-penetrating radar (GPR), as well as their integration with other technologies such as infrared imaging, GPS, and RFID. While these two types of technologies individually offer significant performance improvements in all parts of the sector, it is their integration that promises to provide the most benefits. Integrated, the two types of technologies would form a cyber-physical system that would deliver bi-directional interoperability, allowing seamless coordination between the virtual worlds captured in the BIM model and the real-world construction. Yet, it is interesting to note there are very few software solutions that enable the joint visualisation and manipulation of 3D imaging and BIM data/information. Furthermore, none of those solutions are based on the combined use of open standards and tools, thereby limiting the extent to which researchers can develop and test new solutions to increase the value of both BIM and 3D imaging technologies. This clearly demonstrates the need for an open-source software platform (based on open-source standards and tools) supporting the management and processing of BIM and 3D imaging data, particularly point clouds, for facility lifecycle management. The paper first builds a case for the need for such a solution, identifying critical Virtual-to-Real, Real-to-Virtual and Virtual-vs-Real applications. A novel open, web-based core software platform is then proposed that utilises the open standards IFC and E57 for real-time bi-directional interoperability between BIM models and 3D imaging data (especially point clouds). Finally, it is revealed how such a system can be developed and grown over time from industry contributions through an open-source initiative.
The need for Convergence of BIM and 3D imaging in the Open World. Proceedings of the CitA BIM Gathering.
O’Keeffe, S. and Bosche, F.
The authors have developed a novel system framework for a historic preservation system utilising open standards and open source tools. The framework enables the integration of open standard 3D models and GIS in a virtual environment (VE). It also allows the storage and harvesting of data via an open-source web-based central repository, i.e. a BimServer. The framework is designed for bi-directional interoperability when utilised for monument tracking, preservation, conservation, re-excavation, etc. To date, no such system framework exists for the development and management of historic monuments using open standards e57 for terrestrial laser scanning (TLS) data, the industry foundation classes (IFC) for 3D semantic rich models, and CityGML for integrating IFC and GIS in a VE. The convergence of a VE utilising CityGML and the BimServer can afford the bi-directional sharing of data. The web-based VE is accessed online from the BimServer and is intended for monitoring monument erosion, the movement and damage to monuments by human activity or nature, etc. Furthermore, the authors envision that actors such as museum curators, historians, engineers, etc., will benefit greatly from open source sematic rich 3D models. Utilising IFC for historic monuments facilitates collaboration between different industry actors to share knowledge, experience, and expertise globally through a web-based repository. In this paper the authors apply their system framework by converting TLS data of a heritage monument at the Abu Simbel Temple in Egypt into an IFC compliant model. Semantic data is embedded into the model and then stored in a web-based database repository. The IFC model can then be interoperable with the IFC GIS VE, via the web-based system user interface, for many purposes such as georeference data for tracking and excavation purposes. This framework can be employed to develop further open-source systems that maximise efficiency and minimise risk during locating and excavating disturbed monuments.
OpenBIM Framework for a Collaborative Historical Preservation System. Proceedings of the CitA BIM Gathering.
O’Keeffe, S. and Bergin, D.