THREE DIMENSIONAL COMPUTER GRAPHICS DRAWING SYSTEM

A computer graphics system is provided that is based on two fundamental primitives: a ball and a stick. These primitives may be combined to create simple or complex drawings, in accordance with eight specified rules regarding ball and stick geometry, manipulation and representation. The system may be used for education or entertainment as a drawing tool, but may also be used to organize, present and manipulate 3D diagrams ("information structures") representing information organized in a hierarchical manner. There is also provided a range of coordinated graphic user interface (GUI) controls, These controls enable realtime manipulation of ball and stick objects in 3D. The controls include facilities for "extruding" a new ball and stick objects from an existing ball; 3D control "widgets", in which 3D elements within the control are accessed and moved three dimensionally in order to operate the control; 3D color palates; transparent controls that are fully functional but do not hide the work which appears underneath; context-sensitive "sub-cursors". L'invention concerne un système d'infographie basé sur deux primitives fondamentales : une boule et un bâton. Ces primitives peuvent être combinées pour créer des dessins simples ou complexes, en fonction de huit règles spécifiées concernant la géométrie, la manipulation et la représentation de la boule et du bâton. Le système peut être utilisé pour l'éducation ou pour le divertissement comme outil de dessin, mais peut également être utilisé pour organiser, présenter et manipuler des diagrammes 3D (