The Hong Kong University of Science and Technology
Department of Computer Science and Engineering


PhD Thesis Defence


"Differential Techniques for Scalable and Interactive Mesh Editing"

By

Mr. Kin-Chung Au


Abstract

Meshes is the most common representation for 3D surface models nowadays
and there is a great demand for processing mesh models. Editing existing
meshes is challenging because the editing is limited by the original mesh
structure, namely, the irregularities of the vertex distribution and the
connectivity. A desirable editing framework should satisfy the users'
editing intentions while maintaining the original shape features as much
as possible. Therefore the description of the shape features is crucial
and has a direct relation on the quality of the editing system.

In this thesis we propose a new non-linear differential editing framework,
based on the curvature flow Laplacian coordinates, for efficient editing
of irregular meshes. This framework overcomes the main limitation of
earlier linearized methods, specifically, it solves the common
transformation problem of differential editing and avoids undesirable
distortion under large-scale rotations and translations of the handles. In
addition, our framework supports a new type of handles, point-handle,
which enables automatic orientation estimation, thus further simplifying
the user interface. To further improve the stability of our editing
framework for editing meshes with poor sampling rates and triangle
quality, we then propose to edit the meshes in the dual domain, using the
dual Laplacian coordinates.

Meshes created by modern scanning technology are typically huge. Editing
such meshes using a nonlinear editing framework gives unacceptable slow
performance. To solve this problem, we introduce the notion of
handle-aware rigidity based on the observation that for each vertex the
influence of deformations received from different handles is largely
dependent on the locations of the handles on the mesh, and independent of
the handles' movement during deformation. We present a general reduced
model based on handle-aware isolines, enabling interactive editing of huge
models with physically plausible deformation results.


Date:			Tuesday, 28 August 2007

Time:			3:00p.m.-5:00p.m.

Venue:			Room 3301A
			Lifts 17-18

Chairman:		Prof. Zhenyang Lin (CHEM)

Committee Members:	Prof. Chiew-Lan Tai (Supervisor)
			Prof. Long Quan
			Prof. Pedro Sander
			Prof. Kai Tang (MECH)
			Prof. Pheng-Ann Heng (CSE, CUHK)


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