This section explores the essential role of open formats in the context of BIM, with a primary focus on IFC and its Model View Definition (MVDs) as well as other existing formats such as JSON or GLTF.
The use of open formats in the Architecture, Engineering and Construction software sector provide the foundation for effective collaboration and data exchange. In the current panorama embracing open formats is not just a choice for this sector, but a necessity, empowering stakeholders to harness the full potential of BIM, driving efficiency, accuracy, and innovation.
IFC is an open and neutral data format that plays a central role in BIM. Developed by buildingSMART, it is a common language that allows different software applications used in the construction industry to communicate seamlessly. IFC supports the exchange of 3D models, 2D drawings, and non-geometric data, making it versatile for all phases of a building's life cycle.
Industry Foundation Classes (IFC) is a standardized, digital description of the built asset industry. It is an open, international standard (ISO 16739-1:2018) and promotes vendor-neutral, or agnostic, and usable capabilities across a wide range of hardware devices, software platforms, and interfaces for many different use cases.
MVDs define specific subsets of the IFC schema tailored to the needs of particular stages or aspects of a construction project. For instance, an MVD for energy analysis might include data related to insulation materials, heating, and cooling systems.
Model View Definition (MVD) is a specific implementation level of IFC to describe and to facilitate a specific use or workflow. There are three (base) MVDs which are the levels of implementation of IFC:
Exchange requirements can be defined on top of the (base) MVD. This will increase the interoperability between domains.
Information Delivery Specification (IdS) is a computer interpretable document that defines the Exchange Requirements of model based exchange. It defines how objects, classifications, properties, and even values and units need to be delivered and exchanged. This can be a combination of Industry Foundation Classes (IFC), Domain Extensions, and additional classifications and properties (national agreements or company specific ones; either stored in bSDD or somewhere else).
While IFC serves as the backbone of BIM, other open formats like JSON (JavaScript Object Notation) and GLTF (GL Transmission Format) also have their roles to play.
JSON, known for its simplicity and human-readability, is used for data exchange and communication in web-based BIM applications. Its lightweight structure allows for fast data transmission and easy integration with other technologies, making it a valuable addition to the BIM ecosystem.
JSON is a lightweight data-interchange format. It is easy for humans to read and write. It is easy for machines to parse and generate. It is based on a subset of the JavaScript Programming Language Standard ECMA-262 3rd Edition - December 1999. JSON is a text format that is completely language independent but uses conventions that are familiar to programmers of the C-family of languages, including C, C++, C#, Java, JavaScript, Perl, Python, and many others. These properties make JSON an ideal data-interchange language.
GLTF is a 3D file format optimized for web delivery and real-time rendering. It is particularly valuable for visualizing BIM models in web browsers and virtual reality environments. By enabling easy access to 3D data, GLTF enhances communication and decision-making throughout the project lifecycle.
GLTF is a royalty-free specification for the efficient transmission and loading of 3D scenes and models by engines and applications. glTF minimizes the size of 3D assets, and the runtime processing needed to unpack and use them. glTF defines an extensible, publishing format that streamlines authoring workflows and interactive services by enabling the interoperable use of 3D content across the industry. glTF 2.0 has been released as the ISO/IEC 12113:2022 International Standard.
Public administrations can play a pivotal role in promoting IFC adoption by requiring its use in government-funded construction projects. By mandating IFC compliance, public agencies can drive the industry toward a unified, interoperable, and open standard, ensuring that taxpayers' money is invested wisely in projects that benefit from BIM's advantages.
Public administrations can promote the use of MVDs by developing standardized templates that align with their specific requirements. By providing these templates to project stakeholders, public agencies can ensure that critical data is consistently included in BIM models, improving the accuracy of assessments, inspections, and regulatory compliance checks.