Line art rendering via a coverage of isoparametric curves

A line-art nonphotorealistic rendering scheme of scenes composed of freeform surfaces is presented. A freeform surface coverage is constructed using a set of isoparametric curves. The density of the isoparametric curves is set to be a function of the illumination of the surface determined using a simple shading model, or of regions of special importance such as silhouettes. The outcome is one way of achieving an aesthetic and attractive line-art rendering that employs isoparametric curve based drawings that is suitable for printing publication.