This thesis describes the definition and fairing scheme of ship hull using a B-spline tensor product surface. In our definition scheme of ship hull, the surface is defined by a network of control points which are initially obtained from longitudinal curves or water lines on ship hull. Then the ship hull is represented completely as a 3-D geometric model by B-spline tensor product surface. Fairing the ship hull is accomplished by controlling the network of control points or surface points in three projection planes using a graphic CRT. All the drawings such as isometrice views of whole ship hull, body plan, water lines, and buttock lines can be generated quickly by the subdivision technique of B-spline surface. And for a detailed inspection of fairness of surface, we use the contour map of Gaussian curvature isloines for the indicator of fairness.
For the experimental application of our new scheme to the definition and fairing of real ship hull, we have developed a prototype software package by FORTRAN language on PRIME 750 computer system, which provides the facilities such as Curve Editor, fast rendering of B-spline surface, and contouring of Gaussian curvature isolines, and the relevant algorithms such as B-spline surface interpolation, subdivision of B-spline surface, and intersection of two B-spline surfaces are also developed in this package.
본 논문은 B-spline 곡면을 이용한 선체 표면의 정의 및 Fairing 방법을 논의 하였다. 선체 표면은 Water lines로부터 B-spline 역보간에 의하여 얻어지는 Control Vertices들에 의해서 정의되고 이들 점들을 Graphic CRT상에서 조정하여 Fair한 선체 표면을 형성한다. 결과적으로 선체표면은 B-spline 텐서 곱의 표현으로 모델링 된다. 특히 선체 표면의 자세한 Fairness를 확인하기 위하여 Gaussian 곡률 등고선을 이용하였다.
선체 표면의 정의가 끝나면 Water lines, Body plan등의 단면도는 두 B-spline 곡면의 교차곡선 계산 알고리즘에 의해서 구해진다.
이와 같은 본 논문에서 제시한 방법을 실제 선체표면 정의 작업에 효과적으로 적용하기 위하여 FORTRAN 언어로 Prototype 프로그램을 개발 하였다.
