This paper presents an accurate and efficient method for dynamic animation of one-dimensional objects modelled as successions of spline segments. At each time step the object shape conforms to its splines definitions, thus insuring that every property implied by the nature of the chosen splines is verified. This fact is achieved by the animation of the control points of the splines. However, as in [Terzopoulos 94] and [Qin 96] for the D-NURBS, these control points are not considered as weighty points but moreover as the degrees of freedom of the continuous object. The chosen dynamic equations (Lagrangian formalism) reflect this modelling idea and yield to an accurate and very efficient linear system. Suitable handling of forces and constraints, and numerical resolution are discussed in this scheme too.

Keywords: Simulation, Dynamic animation , Lagrangian equations, spline animation.