High Quality Content by WIKIPEDIA articles! Solid modeling software originally used either constructive solid geometry (CSG) or Boundary representation (B-REP) techniques to define solid shapes Beginning in the late 1980s, software developers began applying higher-levels of abstraction to solid modeling construction techiques The first ожудл of these techniques, called parametric feature-based solid-modelling, was introducted in commercial software by Parametric Technology Corporation in September 1987 These approaches made solid-modeling software easier to use and increased its acceptance among mechanical engineers.  В пособии2010 г Мягкая обложка, 108 стр ISBN 6130346638.