Bourguignon, DavidChaine, RaphaelleCani, Marie-PauleDrettakis, GeorgeJoaquim Armando Pires Jorge and Eric Galin and John F. Hughes2014-01-272014-01-2720043-905673-16-91812-3503https://doi.org/10.2312/SBM/SBM04/151-160This paper presents a modeling system which takes advantage of two-dimensional drawing knowledge to design three-dimensional free-form shapes. A set of mouse or tablet strokes is interpreted by the system as defining both a two-dimensional shape boundary and a displacement map. This information is used for pushing or pulling vertices of existing surfaces, or for creating vertices of new surface patches. To relieve the burden of 3D manipulation from the user, patches are automatically positioned in space. The iterative design process alternates a modeling by drawing sequence and a viewpoint change. To stay as close as possible to the traditional drawing experience, the system imposes the minimum number of constraints on the topology of either the strokes set or the resulting surface.