A method and apparatus is presented in which a physical object is formed on the basis of data that represents a free-form surface. A free-form surface is formed by entering into a designing device a series of input points. A free-form surface forming unit of the designing device then generates geometric...http://www.google.co.uk/patents/US6084586?utm_source=gb-gplus-sharePatent US6084586 - Method and apparatus for forming objects based on free-form curves and free-form surfaces generated by minimizing sum of distances from an input series of points to a free-form curve
