Friday, October 13, 2006
Crowd Simulation Workshop
This week, I had the exciting opportunity to attend a private workshop on pedestrian and crowd simulation at the University of Pennsylvania in Philadelphia. Hosted by Director Ali Malkawi PhD and Nuria Pelechano, PhD candidate of UPenn's Center for Human Modeling and Simulation, we participated in an excellent discussion about the objectives, requirements and potential limitations of such simulations.
We learned a great deal about STEPS software from Mott MacDonald as we created "people groups" and "events" which help form a simulation relative to the behavior of certain types of actual humans. Patience level, walking speed and type of event (emergency vs. normal movement) all help to customize the values you're trying to extract from the simulation. Keep in mind that the more expensive simulation packages might not be as slick as some others, but you're paying for the calibration - the amount of real performance data the software developers collect and compare with their simulation algorithms.
Most crowd simulation programs use certain flavors of cellular automata - essentially pixelating the floor plan and allowing each cell or pixel to be occupied or vacant. Like a tic-tac-toe grid, when the center square is occupied, the program constantly analyzes the eight possible surrounding cells for the least resistant path, thus creating a motion path for each of the occupants much like moving on a checkerboard.
I'm also reminded of a passage from André Chaszar's recent book "Blurring the Lines" in which he reminds the reader of a specialized knowledge that must be applied to the results of any computerized simulation. In other words, the results are only as good as the professionals interpreting those results.
In summary, such simulation tools are quite exciting to use as part of the design process; however, most tools still don't have the ability to efficiently share 3D data from Architectural design applications. Analysis programs such as Simulex from IES have been working for us in generating simple, one floor occupant simulations based on exported floor plans from Revit, but we still have to apply an overlay of data to the points of egress. I'll post more details as we make more progress with these tools.
Other crowd simulation tools for Architectural and gaming simulations: EXODUS, viCROWD, LEGION, OpenSteer