•   When: Friday, April 27, 2018 from 11:30 AM to 01:30 PM
•   Speakers: Songrun Liu
•   Location: ENGR 1602
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Smooth shape deformation has become a vital tool for the animation and design of 2D and 3D shapes. Linear methods, under the umbrella term of “linear blend skinning”, are the de facto standard for 3D animations. This thesis aims to broaden the application scope of these approaches by either overcoming existing limitations or exploring new directions.

Linear blend skinning does not trivially extend to deforming vector graphics, such as the cubic Bezier splines prevalent in 2D or subdivision surfaces in 3D. We propose a variational approach to reposition the control points of cubic Bezier splines and Catmull-Clark subdivision surfaces—or any linear subdivision curves or surfaces—to produce curves or surfaces which match a linear blend skinning deformation as closely as possible. We support C₀,C₁,G₁, and fixed-angle continuity constraints between adjacent Bezier curves in a spline. Complexity scales linearly with respect to the number of input curves and run-time performance is fast enough for real-time editing and animation of high-resolution shapes.

When skinning a triangle mesh, the space of deformations is limited by the coarseness of the discretization. Texture images storing parameterized skinning weights decouples the resolution of weights from the resolution of the surface geometry. Unfortunately, seams are inevitable when parametrizing most surfaces. We present seam-aware mesh processing techniques. Our algorithms eliminate seam artifacts in parameterized signals and decimate a mesh—including its seams—while preserving its parameterization and seam-free appearance. This allows the artifact-free display of various surface signals, including linear blend skinning weights, with the standard GPU rendering pipeline.