NPSNETIV : an object-oriented interface for a three-dimensional virtual world

Abstract

All simulations require some type of user interface to be functional. The problem is that this interface is sometimes written as a tightly coupled part of the simulation itself, buried in the main body of code. This makes the interface very difficult to create, and once created, more difficult to alter. Thus these tightly coupled simulations do not support a simple way to prototype new interface models and incorporate them into the application. The solution is to segregate the interface from the main simulation in a loosely coupled system. Communication with the application is through a well-defined interface. By separating the two, changes can easily be incorporated into either module without significant impact on the other. The approach taken was to create the interface as a separate program. Communication with the main simulation is through data structures passed over a socket communications link. The resulting application displays a control panel on a separate monitor. Using object- oriented techniques, components are defined, incorporated, rearranged, and deleted from the panel as needed. The loose coupling to NPSNET means that changes made to one application have little effect on the other. New interfaces can now be quickly and easi y created without effecting the core NPSNET application to any significant degree.