REPRESENTATION PARADIGMS FOR MASONRY MODULATION IN BIM TOOLS

Abstract

New CAD tools which support the BIM (Building Information Modeling) concept are based on 3D-modeling buildings by instancing objects from component families. Some of these objects have detailed geometry while others are restricted to their outer boundaries. In the “wall object” case, this representation usually is limited to its external faces and a list of layers is used to represent its internal composition (core and finishes). This representation makes the file light, helping the application performance. However, in designs that require a higher detail level than this solution supports, like the masonry design for production (MDP), a complete 3D representation of wall components is important. In this context, a question arises: how to represent the wall elements in a way that fulfills the MDP requirements and, at the same time, do not degrade the handling performance of the BIM model? This work presents some approaches to representing masonry modulation: an explicit one (object families) and some others implicit (array / generative modeling). A comparative analysis is presented, highlighting their pros and cons like implementation complexity, ease of use and performance impact on the application. The feasibility of each method was studied on Autodesk Revit® Architecture 2009/2010 considering processing for generating 2D views and quantity take off, as well as memory and CPU consumption for each approach, enabling decision making at the implementation level.