Abstract：The angle between two connected curves on same quadric is defined and two minimum internal angle algorithms(MIA_cw and MIA_ccw) that can be applied to quadric surfaces are proposed. When a circle is searched by MIA_cw or MIA_ccw, the vector mixed product is employed to verify whether the circle is a candidate surface or not. In the proposed method, no matter which curved edge of wireframe model is chosen, the candidate surface containing it can be obtained. Thus, it removes the restriction on the start edge in searching candidate surface in existing methods. The candidate surface with curves is separated from those without curves by the proposed method and different algorithms can be used for these two kinds of candidate surfaces. And it requires less time than the one using one algorithm to search all candidate surfaces (including quadric surface and plane surface). Furthermore, the proposed method can deal with the 3D wireframe models with no restriction on the axis of the quadric surface and identify the type of the quadric.
2011, Vol. 24 
