  Point masses connected by springs, or mass-spring systems, are widely used in
computer animation to approximate the behavior of deformable objects. One of
the restrictions imposed by these models is that points that are not
topologically constrained (linked by a spring) are unable to interact with each
other explicitly. Such interactions would introduce a new dimension for
artistic control and animation within the computer graphics community. Beyond
graphics, such a model could be an effective proxy to use for model-based
learning of complex physical systems such as molecular biology. We propose to
imbue masses in a mass-spring system with electrostatic charge leading a system
with internal forces between all pairs of charged points -- regardless of
whether they are linked by a spring. We provide a practical and stable
algorithm to simulate charged mass-spring systems over long time horizons. We
demonstrate how these systems may be controlled via parameters such as guidance
electric fields or external charges, thus presenting fresh opportunities for
artistic authoring. Our method is especially appropriate for computer graphics
applications due to its robustness at larger simulation time steps.
