1. A computerized method for using curves to construct and control a geometric model of at least one physical object for simulation, animation or visual communication by a computer, said method comprising the steps of: (a) providing to the computer a geometric model representing a physical object, at least a portion of the topography of the surface of said physical object being controlled by an underlying muscle mechanism of deformation of said physical object; (b) providing and locating at least one control curve in the model based on the topography of said model such that modification of at least a section of said control curve has an effect on the topography of the model that is geometrically analogous to the effect of movement of the underlying muscle mechanism of deformation has on the topography of the surface of said physical object; (c) associating elements of said model with elements of said at least one control curve by the computer so that said curves control movement of said elements of said model; (d) dynamically modifying said at least one curve so that said model is dynamically changed so as to simulate the effect of the movement of the underlying muscle mechanism of deformation on the topography of the surface of the object to move a particular point on said surface to a different location, wherein said modifying of said curves is integral to simulating movement in the model equivalent to movement due to the underlying muscle mechanism of deformation of the physical object; and (e) displaying the dynamically changed model.