An optimisation-based reconstruction engine for 3D modelling by sketching

An engine that automatically reconstructs a large variety of polyhedral, origami and wire-frame objects from single-view sketched drawings generated in a calligraphic interface is presented. The engine has two stages. An innovative optimisation-based line-drawing beautifier stage is introduced to convert rough sketches into tidied-up line drawings. Optimisation-based 3D reconstruction follows. Solutions are provided with which to overcome the problems associated with earlier approaches to optimisation-based 3D reconstruction. Suitable adjustments in the optimisation algorithms are proposed; simple and efficient tentative models are introduced, and current regularities are categorised in order to allow the objective function to be simplified. All three actions help to prevent local optima and improve the computational efficiency of optimisation-based 3D reconstruction. They all proved to be effective techniques to reduce the typical failure rate of optimisation approaches. A discussion of results that validate the engine is also provided.1) “Generalitat Valenciana”, under its grant programme for Technological Research and Development (Project GV97-TI-04-39, entitled “3D Object Reconstruction from 2D Representations” 2) Universitat Jaume I (“Plan 2002 de promoció de la investigació a l’UJI”, Project P1-1B2002-08, entitled “From sketch to model: new user interfaces for CAD systems”)