Introduction of Physics Simulation in Augmented Reality

In 3D computer graphics, it has been an important issue to describe a virtual object realistically and show it in a physically correct manner. Unlike the virtual reality(VR), the augmented reality (AR) is an environment containing virtual and real objects simultaneously. However, the difference in motion between the virtual and real objects is obvious, which makes it hard for AR to be realistic and attractive. To reduce this gap, we propose to apply physical attributes to each virtual object, which can be done by using a physics engine, a software library containing functions related with physics. For this purpose, an ODE (open dynamics engine) library is used. However, the direct use of the library in the AR environment poses a lot of problems. Most of all, the coordination of the coordinate systems between OSG (OpenSceneGraph) and ODE must be taken care of. Next the positions of markers are also needed to be considered. In this paper, such problems are addressed and solutions to them are discussed.