Combining 2D and 3D data through Geodatabase

I stumbled across an interesting powerpoint presentation from the UC ESRI Conference in 2007. It's about a hybrid data model for fire evacuation and is very similar to the project I am currently working on. It was proposed by Inhye Park from the University of Seoul, Korea.

The "hybrid" model proposes that a 2d environment maintained in GIS and a 3D environment created somewhere else, all linked together through the Geodatabase using SQL calls.

Here is an example from the presentation:

The first part, converting the CAD files to Geodatabase files, I have already completed. The database has been build, but we have yet to link it to any other 3D data models yet. This is what we hope to accomplish in the coming weeks.

Below is a graphic depicting how the model will work once completed: