Sketching Free-form Surfaces Using Network of Curves

This work addresses the issue of generating free-form surfaces using a 2D sketch interface. As the first step in this process, we develop a methodology to sketch 3D space curves from 2D sketches. Since the inverse projection from 2D sketches to 3D curve or surface is a one to many function, there is no unique solution. Hence we propose to interpret the given 2D curve to be the projection of the 3D curve that has minimum curvature among all the candidates in 3D. We present an algorithm to efficiently find a close approximation of this minimum curvature 3D space curve. In the second step, this network of curves along with the boundary information are given to the surface fitting method to generate free-form surfaces.