Illustration of Smooth Isosurfaces

We present in this paper a new particle-based method for sampling and rendering several types of the nonphotorealistic feature contours on implicit surfaces: silhouette, shadow and suggestive contours. We introduce a curve adhesion behavior for dynamic particles that brings up the possibility to render any contour that is defined as an intersection of two smooth implicit surfaces. In the case of the smooth contours, we construct and maintain polylines with correct topology, by connecting the particles that adhere to these contours. We implement a new visibility algorithm for silhouettes, based on a planar map constructed with the projections of the zero radial curvature and silhouette contours onto the image plane. We present several images rendered in our framework, thus demonstrating that we introduce a powerful tool for the real-time viewdependent visualization of the feature contours on smooth implicit surfaces and more generally, of any implicitly defined contours. CR Categories: I.3.7 [Computer Graphics]: Three-Dimensional Graphics and Realism—Color, shading, shadowing, and texture; I.3.7 [Computer Graphics]: Three-Dimensional Graphics and Realism—Visible line/surface algorithms