| 摘要 |
PURPOSE:To improve calculation efficiency for graphic operation by providing virtual data, in which a surface is suspectedly displayed as a solid, as graphic data and executing the graphic operation based on these virtual data. CONSTITUTION:A storing means 6 stores real data concerning rigid lines constituting a graphic, namely, geometrical data concerning the apex of the rigid line, the rigid line connected to the apex, the real surface sharing the rigid line the rigid line, data showing the type of the rigid line (straight line or curved line) and the virtual data constituting the graphic, namely, the data of the virtual surface (virtual surface) sharing the rigid line. Based on an instruction to be outputted from a command output means 5, a graphic operating means 1 takes out the data, which are stored in the storing means 6, and executes the graphic operation. Accordingly, the virtual data can be calculated and the graphic operation can be executed without fail mutually between curved surfaces, between the curved surface and solid, and mutually between the solids. Thus, the calculation efficiency for the graphic operation is improved. |
