The design and visualization of three-dimensional objects with curved surfaces have always been difficult. This paper describes a computer system that facilitates both the design and visualization of such surfaces. The system enhances the design of these surfaces by virtue of various interactive techniques coupled with the application of B-Spline theory. Visualization is facilitated by including a specially built model-making machine that produces three-dimensional foam models. Thus the system permits the designer to define an object and, with little additional effort, produce an inexpensive model of the object which is suitable for evaluation and presentation.