C.Shaw; Free-Form Surface Sketching Using Two-Handed Input, 28.11.2005

Free-Form Surface Sketching Using Two-Handed Input

Assoc.Prof. Chris Shaw
School of Interactive Arst and Technology,
Simon Fraser University Surrey, British Columbia, Canada

Abstract:
A free-form deformation that warps a surface or solid may be specified in terms of one or several point-displacement constraints that must be interpolated by the deformation. Our Twister adds the capability to impose an orientation change, adding three rotational constraints, at each displaced point. Furthermore, it solves for a space warp that simultaneously interpolates two sets of such displacement and orientation constraints. With
a 6 DoF magnetic tracker in each hand, the user may grab two points on or near the surface of an object and simultaneously drag them to new locations while rotating the trackers to tilt, bend, or twist the shape near the displaced points. Using a new formalism based on a weighted average of screw displacements, Twister computes in realtime a smooth deformation, whose effect decays with distance from the grabbed points, simultaneously
interpolating the 12 constraints. It is continuously applied to the shape, providing realtime graphic feedback. The two-hand interface and the resulting deformation are intuitive and hence offer an effective direct manipulation tool for creating or modifying 3D shapes.

Bio:
Chris Shaw is an Associate Professor at the School of Interactive Arts and Technology, Simon Fraser University Surrey, in British Columbia, Canada. Shaw received a B Math in Computer Science from the University of Waterloo in 1986, an MSc in Computing Science from the University of Alberta in 1988, and the Ph.D. in Computing Science from the University of Alberta in 1997. Shaw is Co-Architect of the MR Toolkit, which is VR software that has been licenced by 600 research institutions worldwide since 1993.

November 28, 2005, 14:40, L063