高密度測定点データに基づく自由曲面生成法に関する研究(第2報)

擬頂点を用いた曲線・曲面の接続法

抄録

Acquiring profile data and producing CAD models are indispensable to style designing based on a master model. Therefore the present studies aim to generate high-quality CAD models from measured point data on a master model which has free-form surfaces. In the former report, a method to measure a master model, that is, boundary high-density measuring, and a method of character-area extracting were proposed. This paper describes a strategy of remeasurement in extracted character-areas and one technique to generate free-form surfaces from the measured point data acquired by the remeasurement. The master model is measured with a non-contact 3-D digitizing system developed by the authors. In the remeasurement, a patch on each hierarchical structure is divided into four parts in a quadtree method, and a uniform cubic B-spline curve fits onto the measured point data. The fitted patches are connected to subdivided ones and they together can form the free-form surface of the master model with their adjacent patches conforming to the C2 continuity. New techniques are also proposed for connecting B-spline curves with surfaces by use of pseudo vertices. The results of inspection experiments with the measured point data confirm the availability of those methods.