The PSB (Pressure Soft Body) Model has been developed and published first on the SIGRAD conference in Umea (Sweden), and has been described in details in following paper:
Matyka, M. and Ollila, M. "A pressure model for soft body simulation", Proc. of Sigrad, UMEA, November 2003
So far I am back in Poland and found time to make some improvements in the model. Pictures I am showing there are taken directly from my article:
Matyka, M. "Practical Animation of Soft Bodies for Game Development. The PSB Model.", Game Programming Gems 5 (available in March 2005)
The main reason for developming the PSB model was to create fast and flexible soft body model which allow to simulate deformable bodies at interactive rates (for purposes of some medical/virtual reality/games applications.
The main idea behind the model is to incorporate one (!) additional force, into simple cloth-dynamics engine. This force is based on difference of pressure between inside and outside of the body. For details and physics background behind the model please read those two articles, first of them is available on my web site:
You can also find here some additional materials on my Soft Body model (i.e. Soft Body 3.0 program which is a straighforward implementation of the PSB model). The source code is not available, but technique is quite easy to follow and implement. The source code will be available in March 2005, when Game Programming Gems 5 will be finished. As a bonus, please take a look at new results of my MSc thesis which cover some CFD techniques interesting for graphics community (available on my home page).