Our virtual environment authoring system has several key features. These lie in the areas of scene construction and scripting.  The scene is constructed by placing models within the environment using an easy to use interface to insert sets, position objects, set up object sounds, define custom object properties, lighting, etc.

The scripting system allows users to work at two levels of abstraction. The highest level allows users to visually construct "behaviours" that will determine how objects interact with each other.  As these behaviours are constructed, a coherent English sentence is generated describing the effects of the behaviour.  Behaviours can be of two distinct types, namely templates or explicit.  Template behaviours are generic behaviours that can be created once and then dragged onto objects.  Explicit behaviours are used to define specifically how certain objects behave with each other, essentially providing a mechanism for exceptions.  The overall effect of the template/explicit model is that template behaviours are used to define the general behaviour or
"rules" of objects in the world, whereas explicit behaviours are used to encourage a particular narrative.

At a lesser level of abstraction, it is possible to program both comparators and actions directly to extend the possible set of action and condition types thereby enriching the available set of behaviours. Python is used as the underlying scripting language.  A rich API is made available from Python to enhance the ease of this scripting.