CATHI - Automatic generation of animations

The CATHI system

Computer Animation Tool for Help and Information Systems (see the flying logos FLI 1Mb, FLI 2.3Mb, MPEG 230Kb, ).
The CATHI system is an Animation Script generator. It generates scripts for 3D Animation Sequences expressing given communicative contents based on a grammar-like system of visualization rules. CATHI is based on the view of animation generation as a process that bears similarities with the generation of natural language and takes advantage, to a certain extent, of the transfer of ideas and methods from this field.

The CATHI system is being developed (as my PhD thesis) in the framework of the PPP system, an intelligent multimedia presentation system that presents information about the usage and function of technical devices and produces interactive operating instructions that are adapted to the person interacting with the system.

The generation process (as well of PPP as of CATHI) works incrementally to allow an interactive presentation system to generate animations and show them with a limited delay, which is important for short system response times. In some papers about this work we ( Antonio Krüger and I) have shown which type of incrementality is supported by the system and we've described a way to enhance the results by automatically generated abstractions (simplified 3D models).

Depending on the available graphical output devices and facilities the system may produce animation scripts for simple wire-frame graphics or sophisticated lighting and shading models. The availability of such features as color or spotlights is already considered in the process of script generation. This allows optimal use of the available expressiveness, thus making CATHI a resource-adaptive system. Currently output can be done to Geomview, a scientific visualization tool written at the University of Minnesota, to RenderMan and VRML 2.0 (work in progress).

Here are some example animations produced with the RenderMan interface. Some day I will provide a better way to play with it through the Web via VRML2.