Spline-based Shape Modeling by 3D Sketching

Abstract

The increasing domination of spline-based graphic objects in CAD/CAS has driven a great attention to methods focusing on natural and intelligent free-form shape manipulation. We present a novel sketch-based system for the interactive modeling of a variety of free-form 3D objects using just simple spline sketches. Our technique addresses the issue of the traditional illustrations for depicting 3D subjects, ranging from geometric modeling to progressive refinement. The robust surface interpreters we proposed support NURBS surface construction respecting the designers' different drawing styles, and a so called spline-driven deformation technique provides designer predictable surface edition. In our system the spline strokes are freely sketched in 3D space and they are controlled by 3D dragger, which will produce a sequence of dynamic deformations to facilitate the user to achieve the desired models. The method has been tested with various types of sketches, which are rendered in a 3D environment.