Smart Sketch System for 3D Reconstruction Based Modeling

Current user interfaces of CAD systems are still not suited to the initial stages of product development, where freehand drawings are used by engineers and designers to express their visual thinking. In order to exploit these sketching skills, we present a sketch based modeling system, which provides a reduced instruction set calligraphic interface to create orthogonal polyhedra, and an extension of them we named quasi-normalons. Our system allows users to draw lines on free-hand axonometric-like drawings, which are automatically tidied and beautified. These line drawings are then converted into a threedimensional model in real time because we implemented a fast reconstruction process, suited for quasi-normalon objects and so-called axonometric inflation method, providing in this way an innovative integrated 2D sketching and 3D view visualization work environment.This work was supported in part by the Portuguese Science Foundation grant 34672/99, the European Commission project IST-2000-28169, the Spanish Generalidad Valenciana grant CTIDIB/2002/51 and Fundació Caixa Castelló- Bancaixa under the Universitat Jaume I program for Research Promotion (Project P1- 1B2002-08)