How It Works

CrossShade allows the creation of 3D-looking shaded production drawings from concept sketches. We use artist-drawn cross-section lines to automatically infer surface information across the sketch, enabling 3D-like rendering.

Cross-sections function as an aid to both sketch creation and viewer understanding of the depicted 3D shape. In particular, intersections of these curves, or cross-hairs, convey valuable 3D information that viewers compose into a mental model of the sketch. We use this information to estimate the surface normals.

Combined with conventional shaders, our normals facilitate the creation of shaded drawings as in the gallery below.

   author   = "Shao, Cloud and Bousseau, Adrien and Sheffer, Alla and Singh, Karan",
   title    = "CrossShade: Shading Concept Sketches Using Cross-Section Curves",
   journal  = "ACM Transactions on Graphics (Proceedings of ACM SIGGRAPH 2012)",
   number   = "4",
   volume   = "31",
   year     = "2012",
   url      = ""
Cloud Shao University of Toronto
Adrien Bousseau REVES - INRIA Sophia Antipolis
Alla Sheffer University of British Columbia
Karan Singh University of Toronto
Mike Boers for help with output rendering, Che Yan for sharing her design expertise, Koos Eissen, Roselien Steur, Spencer Nugent and Mike Serafin for allowing us to use their inspiring sketches.