B-2 - Dung T.

This blog post starts with my expression about next topic discussed throughout this week. I believe BIM would become an integral part for my future career, as many of BIM applications have been subscripted by AEC firms recently. Moreover, at my first Co-Op with the city, we had to delay our construction process when a design change was accepted. In fact, if a BIM model of the pipe connection was created, construction could seamlessly continue instead of waiting for 2-weeks due to re-investigating and re-evaluating of the old design. However, I have neither experience nor knowledge about BIM before enrolling in the class, which has haunted me since transferring to Drexel. My blog post may contain ambiguous statements, and I am waiting for our lecture next Tuesday for discussion about BIM.

The first part of Chapter 2: “BIM Design Tools and Parametric Modeling” discussed about the development of object-based parametric modeling. Several researches were conducted to generate three-dimensional model during 1960s. After the introduction of solid modeling in 1973, two modelling techniques has been competed for years: Boundary representation (B-rep) approach and Constructive Solid Geometry (CSG) approach. The first technique developed an object through operations and object arguments, when the second one applied algebraic expressions to define object. Contemporary parametric modeling has been established after the combination of both techniques, as the CSG-like tool acts as a database to create a visual model in the B-rep tool. Frankly, although it is boring to read, the development of object-based parametric modeling established a solid foundation for further techniques that could not be applied until computing power would handle highly complex models.

The development of object-based parametric modeling tools inspired basic capillaries of BIM design applications, which can currently handle more capabilities than a basic 3-D object designing tool (as SketchUp). By involving with different uses, BIM design applications must split into three distinct way to describe: a tool, a platform, and an environment. For instances, BIM environment applications can utilize tools within the application for crafting and managing design database (In other terms, “libraries of objects”). Moreover, most BIM platforms can perform other engineering or management tasks such as structural analysis, energy analysis, rendering, and cost estimating, etc.… through add-ons interfaces. In short, BIM provides a faster, more precise, and affordable option to design, build, and manage a project.

Revit platform was introduced as current market leader for BIM in architectural design by the authors. It is still a best-known BIM platform in the building construction, since Revit has been listed as either required or recommended skills for design jobs. Being an Autodesk product, Revit users can access to Autodesk-provided library (SEEK) for object specification. Also, many vendors create libraries of their products for Revit platform, which supports a big list of file types: RVA, DWG, DWF, DGN, GSM, SKP, IES... Moreover, due to its dominant market position, many add-ons and softwares in diverse sector under civil engineering umbrella have been associated with Revit including structural (STAAD), mechanical (MagiCAD), energy (EnergyPlus), rendering (3D Max), facility management, site analysis (Civil 3D). However, it can only process smoothly for projects lower than 300 MB, and provides limited support for complex structures.

Source:

C.M. Eastman. "Chapter 2: BIM Design Tools and Parametric Modeling" in BIM Handbook: A Guide to Building Information Modeling for Owners, Managers, Designers, Engineers, and Contractors, 2nd ed., Hoboken, NJ: Wiley, 2012 pp.31-97.

Comments:

Kerry, 

Thank you for summarizing the long chapter into 3 paragraphs, which I was used as a guideline to skim through 66 pages of dry writing. I believe Revit has changed drastically than at the time this book was published, and additional options have been added. Similar to Zac comments from above, it is essential for a large multisector company to open a BIM-related modeling department to fully understand about the software as well as the technology

Dee Dee,

Thank you for sharing your Co-Op and Revit experience at your blog post. I really wonder about the central model function of Revit. It is really cool to design models of structural system or MEP system without depending on Architect's model. Also, I am curious what would happen if the architect decide to change a design? Otherwise, it is really cool to know that Revit MEP has developed add-ons for air duct sizing.

Thomas,

A company that can control the interoperability between BIM and its add-ons becomes a winner in this competition. I agree with you on your concern about Autodesk's domination on BIM software, as it is currently the only software company could be able to create Revit-friendly add-ons to fulfill the seamless transition of a model between every software. Collaborations between multiple companies to create a public BIM tools to transfer models between software are good, but then it might lead to an interest group of these companies controlling BIM industry because there is no such thing as a free lunch.