Customizable Strokes for Localized Stylization of View-Dependent Lines Extracted from 3D Models

We propose a method to stylize individual lines and preserve their properties as the viewpoint is modified. As the camera position changes and view-dependent lines move across the surface, we track each line in order to extract and store the areas of the surface in which they appear. Each line has an unique reference that we use to check an indexed table from which we can recover its stylization after arbitrary camera movements. We call this region the tracked area of the line. Additionally, we provide a method for line segmentation of occluding contours. In our algorithm, we divide the contour lines at inflection points in order to segment them in a way that is suited for localized stylization as well as to better approximate artist strokes. We also optimize the line tracking process by making use of the Gaussian curvature to separate the elliptic and hyperbolic areas of the surface. In this paper we show how each line only appears in a limited area of the surface corresponding to its tracked area. We also discuss how to eliminate the over-segmentation caused by numerical instability of the approximations in polygonal surfaces as well as how smoothing can be used in order to deal with highly detailed models. Finally, we highlight the achievements of our system for localized stylization of the contour lines of 3D models.