Sýkora, DanielKavan, LadislavČadík, MartinJamriška, OndřejJacobson, AlecWhited, BrianSimmons, MaryannSorkine-Hornung, Olga2023-05-222023-05-222014-03-012015-11-06https://repository.upenn.edu/handle/20.500.14332/36414We present a new approach for generating global illumination renderings of hand-drawn characters using only a small set of simple annotations. Our system exploits the concept of bas-relief sculptures, making it possible to generate 3D proxies suitable for rendering without requiring side-views or extensive user input. We formulate an optimization process that automatically constructs approximate geometry sufficient to evoke the impression of a consistent 3D shape. The resulting renders provide the richer stylization capabilities of 3D global illumination while still retaining the 2D handdrawn look-and-feel. We demonstrate our approach on a varied set of handdrawn images and animations, showing that even in comparison to ground truth renderings of full 3D objects, our bas-relief approximation is able to produce convincing global illumination effects, including self-shadowing, glossy reflections, and diffuse color bleeding.© ACM 2014. This is the author's version of the work. It is posted here for your personal use. Not for redistribution. The definitive Version of Record was published in ACM Transactions on Graphics, http://dx.doi.org/10.1145/2591011.algorithmsdesignhuman factorscartoonsglobal illuminationnon-photorelasitic rendering2D-to-3D conversionbas-reliefComputer SciencesEngineeringGraphics and Human Computer InterfacesArticle