Level sets methods and implicit functions are steadily gaining ground in image analysis. In this work are introduced alternative and easy methodologies based on control points to interactively process implicit functions. We show that, by using the control point formulation, one can set up very efficient and robust algorithms to quickly perform motion tracking and shape modelling. The level sets are generated using an energy functional. The energy is minimized on a reduced set of control points, which results in cheap algorithms for performing various image analysis tasks