Gravitas : an extensible physics engine framework using object-oriented and design pattern-driven software architecture principles

Abstract

We present a physics engine architecture specifically designed to support a wide gamut of rigid body simulation techniques, algorithms and features via abstraction layers and a modular plug-in mechanism. We corroborate our design through the implementation of the engine framework and a number of plug-ins to enable physics simulations featuring a wide variety of body geometry, spatial representations, forces, constraints and collision and constraint resolution techniques. The engine does not impose a fixed simulation pipeline and hence it is possible to implement many simulation approaches, ranging from the simple impulse-based, retroactive techniques to more complex approaches involving conservative advancement, continuous collision detection and simultaneous constraint resolution. We thus demonstrate that it is practical to architect a generic physics engine framework operating at real time interactive rates on commodity computer hardware We also propose an abstract motion constraint specification and present a number of joint models based upon it, which we subsequently demonstrate by means o1 their software implementation and the derivative results.