About 10 years ago I gave a presentation to the Michigan Simulation Users Group (MSUG) on the role of 2D versus 3D animation.  Computers have gotten faster since then but we are still challenged by the ability of simulation modelers to build models that our computers can’t handle.  That being said, the following question still holds true—

 When should I use 2D versus 3D animation?

Traditionalists feel like 3D animation does not add value to the analysis of a project.  The technophiles in the group often think that everything should be in 3D because its how we see and learn most naturally.  I’ve always drawn the line in a different place. 

If a simulation includes spatial characteristics, it should be modeled to-scale.  Almost every to-scale software package that I have seen does not limit itself to 2D.  For example if I am modeling the movement of forklifts to handle material on a dock, I would rather import a CAD file, place my objects at the appropriate location in the layout, and describe how fast the vehicle can drive.  This is more natural than figuring out the time or distance required for a forklift to move between locations.  If the simulation can derive input information by leveraging information entered about specific objects, by all means, model that way.   I would not use a 3D (to-scale) package to model a call center.  The distance between phones or the layout of the call center does not really matter unless I’m trying to figure out the effect of operators walking to a poorly located break room.

You should let the computer do the calculations whenever possible.  The time to develop the models are nearly identical and the time to update a model is usually much lower when modeled to scale.  Imagine I have my dock area modeled in 3D.  If I need to move docks or move potential storage locations.  I simply move them.  I do not have to figure out how far the new travel distance is or what time different exists.  In a 2D world I also lose the concept of congestion unless I model all potential stopping points as destinations.

So, how does this effect software selection?  You need to consider the types of models you are building.  Do not focus simply on the number of times you are going to use the software or a percieved ease-of-use.  I have not seen an appreciable difference in ease of use when it comes to 2D versus 3D software products.   Often 3D packages are used to solve more complicated problems.  If you apply a 2D software package to a problem that should be solved in 3D (or simply to-scale), you will either make assumptions that can harm the accuracy of the model or you will spend more time wedging the problem in to the normally limited constructs available in a 2D package.