Comparison of simulation-driven construction operations visualization and 4D CAD

Several recent research efforts in visualizing construction are rooted in scheduling. They involve linking activity-based construction schedules and 3D CAD models of facilities to describe discretely-evolving construction "product" visualizations called 4D CAD. The focus is on communicating what component(s) are built where and when. The construction processes or operations actually involved in building them are usually implied. Ongoing research at Virginia Tech focuses on designing automated, simulation-driven methods to visualize, in addition to evolving construction products, the operations and processes that are performed in building them. In addition to what is built where and when, the effort is concerned with visualizing who builds it and how by depicting the interaction between involved machines, resources, and materials. This paper expounds the differences in concept, form, and content between 4D CAD and dynamic 3D visualization of operations simulations. An example of a structural steel framing operation is presented to elucidate the comparison.