Graphics abstraction model for SEICAD
Masanobu Matsuo, Ikuo Kondo, Shinji Tsunoda · ACM SIGDA Newsletter · 1981
The data abstraction approach to design of a Graphics Abstraction Model (GAM) for 3D solid objects and 2D picture views is described. The main idea is to represent graphical objects including instances of certain views by abstraction data types and data abstraction models using functional dependencies, which basically use the algebraic approach. Compound objects constructed by several ACTION operations (ASSEMBLE, UNION, etc.) on primitive 3D entities can be handled as compound entities. Points, lines, and faces are defined as data abstractions. General drawing facilities such as points, lines and faces also can be used by commands under 3D coordinates data.