计算机辅助设计与图形学学报
計算機輔助設計與圖形學學報
계산궤보조설계여도형학학보
JOURNAL OF COMPUTER-AIDED DESIGN & COMPUTER GRAPHICS
2010年
2期
312-317,326
,共7页
细分曲面%逼近型细分方法%3细分方法%曲面插值
細分麯麵%逼近型細分方法%3細分方法%麯麵插值
세분곡면%핍근형세분방법%3세분방법%곡면삽치
subdivision surface%approximation subdivision scheme%3 subdivision scheme%surface interpolation
为了避免用逼近型√3细分方法构造插值曲面过程中出现的烦琐运算,利用√3细分方法极限点计算公式,提出一种用逼近型√3细分方法构造闭三角网格插值曲面的方法. 给定待插值的闭三角网格,先用一个新的几何规则与原√3细分方法的拓扑规则细分一次得到一个初始网格,用√3细分方法细分该初始网格得到插值曲面; 新几何规则根据极限点公式确定,保证了初始网格的极限曲面插值待插值的三角网格. 由于初始网格的顶点仅与待插值顶点2邻域内的点相关,所以插值曲面具有良好的局部性,即改变一个待插值点的位置时,只影响插值曲面在其附近的形状. 该方法中只有确定初始网格顶点的几何规则与原√3细分方法不同,故易于整合到原有的细分系统中. 实验结果表明,该方法具有计算简单、有充分的自由度调整插值曲面的形状等特点,使得利用√3细分方法构造三角网格的插值曲面变得极其简单.
為瞭避免用逼近型√3細分方法構造插值麯麵過程中齣現的煩瑣運算,利用√3細分方法極限點計算公式,提齣一種用逼近型√3細分方法構造閉三角網格插值麯麵的方法. 給定待插值的閉三角網格,先用一箇新的幾何規則與原√3細分方法的拓撲規則細分一次得到一箇初始網格,用√3細分方法細分該初始網格得到插值麯麵; 新幾何規則根據極限點公式確定,保證瞭初始網格的極限麯麵插值待插值的三角網格. 由于初始網格的頂點僅與待插值頂點2鄰域內的點相關,所以插值麯麵具有良好的跼部性,即改變一箇待插值點的位置時,隻影響插值麯麵在其附近的形狀. 該方法中隻有確定初始網格頂點的幾何規則與原√3細分方法不同,故易于整閤到原有的細分繫統中. 實驗結果錶明,該方法具有計算簡單、有充分的自由度調整插值麯麵的形狀等特點,使得利用√3細分方法構造三角網格的插值麯麵變得極其簡單.
위료피면용핍근형√3세분방법구조삽치곡면과정중출현적번쇄운산,이용√3세분방법겁한점계산공식,제출일충용핍근형√3세분방법구조폐삼각망격삽치곡면적방법. 급정대삽치적폐삼각망격,선용일개신적궤하규칙여원√3세분방법적탁복규칙세분일차득도일개초시망격,용√3세분방법세분해초시망격득도삽치곡면; 신궤하규칙근거겁한점공식학정,보증료초시망격적겁한곡면삽치대삽치적삼각망격. 유우초시망격적정점부여대삽치정점2린역내적점상관,소이삽치곡면구유량호적국부성,즉개변일개대삽치점적위치시,지영향삽치곡면재기부근적형상. 해방법중지유학정초시망격정점적궤하규칙여원√3세분방법불동,고역우정합도원유적세분계통중. 실험결과표명,해방법구유계산간단、유충분적자유도조정삽치곡면적형상등특점,사득이용√3세분방법구조삼각망격적삽치곡면변득겁기간단.
To avoid the complex computation in the process of interpolating triangular mesh by √3 subdivision scheme, we propose a simple and efficient algorithm for interpolating closed triangular meshes by √3 subdivision scheme using the limit point formula of √3 subdivision scheme. Given the interpolated triangular mesh, by subdividing it with a new geometric rule and the topology rules of √3 subdivision scheme we obtain an initial mesh, whose limit surface of √3 subdivision scheme is the interpolation surface; the new geometric rule is determined by the limit point formula of √3 subdivision scheme, and assure that the limit surface of initial mesh interpolate the given triangular mesh. The new points of initial mesh are defined by the interpolated vertices and their 2-neighborhood vertices, so the interpolation method is local, i.e. the perturbation of a given vertex only influences the surface shape near this vertex. The geometric and topology rules of our interpolation method are the same as those of the √3 subdivision scheme except the first geometric rule of obtaining the initial mesh, so it is very easy to incorporate our method to the origin subdivision system. Numerical examples show that the new interpolation method has many advantageous properties, such as simplification, having enough freedoms to adjust the shape of the interpolation surfaces, and so on. These features make surface interpolation using √3 subdivision scheme very simple.