|dc.description.abstract||When prototyping or developing a system for use in research work, it is often necessary to create an entire system, even if only one part of the system is the focus of the research. Free | open-source software offers a solution to this problem, allowing the creation of cost-effective research platforms, utilising peer-reviewed, rapidly-developed code that is easily modified. One form of free | open-source software that is regularly used in research projects is engines from 3d games such as Unreal Tournament (Lewis & Jacobson, 2002). Although the core rendering engine is proprietary, the game engine is able to be freely utilised as a reasonably generic rendering engine and physics simulator, and most of the game code is modifiable.
A synthetic characters development project, outlined in this paper, uses the Unreal Tournament game engine, via the Gamebots socket tool, as its primary output system. Several other free | open-source software packages are utilised, including a speech recognition system (Sphinx from Carnegie Mellon University), a speech generation system (Festival-Light from Carnegie Mellon University), and a vision system built with Lego™ Mindstorms™ (and the open-source NQC), cheap web-cameras and Intel®’s OpenCV library. These modules all communicate via standard network sockets and are able to operate independently. Each module required a different level of modification in order to form part of the synthetic actors system, from no modification at all (Unreal Tournament), to light modifications (Festival-Light), to a new system based on open-source code (the NQC-based tripod code); one package – the OpenCV library – is simply linked to by completely new code.||en