Computer simulation modelling is growing to be more and more valuable in the design of theatre and move sets. While even a few years ago a designer might make a detailed floor plan drawing of a design and back that up with a small model, sort of like a diorama, done as close as possible to scale, more and more designers are using computer programs to make three dimensional models that way.
The best part of this is that especially in a set with many changes or with pieces that move in some way, this can show the way the pieces and parts might work together to show the scene changes, something much harder to do on a physical model.
Many designers still enjoy creating physical models, and feel these have advantages, and many directors and producers still appreciate seeing the physical creation of the space. Generally, though, they are becoming more a thing of the past in favor of computer imaging.