Direct manipulation of blendshapes using a sketch-based interface

We introduce a method that localizes the direct manipulation of blendshape models for facial animation with a customized sketch-based interface. Direct manipulation methods address the problem of cumbersome weight editing process using the traditional tools with a practical "pin-and-drag" operation directly on the 3D facial models. However, most of the direct manipulation methods have a global deformation impact, which lead to unintuitive and unexpected results. To this end, we propose a new way to localize the theory of direct manipulation method, using geodesic circles for confining the edits to the local geometry. Inspired by artists' brush painting on canvas, we additionally introduce a sketch-based interface as an application that provides direct manipulation and produces expressive facial poses efficiently and intuitively. Our method allows the artists to simply sketch directly onto the 3D facial model and automatically produces the expeditious manipulation until the desired facial pose is obtained. We show that localized blendshape direct manipulation has the potential to reduce the time-consuming blendshape editing process to an easy freehand stroke drawing.