セル構造化幾何モデルとそのモデリングシステム

抄録

The Cell-Constructed-geometric-Model (CCM) is proposed as a new conception for the data representation of geometric model. The CCM consists of three-dimensional array of some finite Cells. The Cell means a unit volumetric solid bounded by six curved surfaces, and is regarded as an extended idea of bi-cubic parametric surface interpolation to a tri-cubic one. The interpolative method of the CCM is a rational cubic Bézier's. Therefore, with the CCM, it is possible to represent a closed volumetric solid bounded by some analytic surfaces and sculptured surfaces using the same data structure. This paper describes the mathematical formulation and the internal data structure of the CCM. Then the application of the CCM to the geometric model for CAM system, Finite-Element-Analysis, and calculation of weight and volume of a solid, are considered. Finally, developed geometric modelling system and methods of modelling to make the CCM interactively are described, and a modelling example of the CCM is shown.