The simulation of deformable objects is a challenging task in the
creation of virtual environments. We present two important cases,
the case of 2D deformable objects, having its application in the
interactive simulation of virtual clothing and the case of
volumetric deformable objects with an application in virtual
surgery. Especially in the latter case special care has to be
taken to reproduce the measured complex viscoelastic properties of
human soft tissue [1]. Semi-discretising
the resulting PDE in space leads to a large system of stiff
ordinary differential equations which has to be solved in
real-time. This can be achieved by using an appropriate
combination of numerical integration methods and iterative
(non-)linear system solvers
[2,3].