Precise Ink Drawing of 3D Models

Abstract

Drawings made with precise pen strokes accurately reveal the geometric forms that give subjects their characteristic shape. We present a system for non-photorealistic rendering of precise drawing strokes over dense 3D triangle meshes with arbitrary topology. During an automatic pre-process, we construct an extended version of the edge-buffer data structure to allow the calculation of shape measures at each mesh edge, by adapting numerical methods used in geomorphology. At runtime, feature edges related to shape measures are extracted and rendered as strokes with varying thickness and pen marking styles. Stroke thickness is automatically adjusted by considering surface curvature. Pen marking styles and visual effects of ink distribution are both controlled by the user. We demonstrate precise drawing strokes over complex meshes revealing a variety of shape characteristics.