Methods and apparatus for generating an N-sided patch by sketching on a three-dimensional reference surface

摘要

Methods and apparatus for generating an n-sided patch by sketching on a three-dimensional reference surface. A user draws a closed curve on a 3D surface; the drawn outline is taken as a boundary for an N-sided patch. If the user does not close the curve, the system may automatically close the curve, as a closed outer boundary curve may be required to produce an N-sided patch. The boundary conditions, the positions, and the surface normals at the boundary are inferred automatically from the 3D surface that the user has drawn the curve on. In addition, boundary curves for the same patch may be drawn on different 3D shapes; multiple 3D shapes may be used as the template or canvas on which the user draws curves from which a patch is to be generated.