Sketch Based 3D Character Deformation

Most 3D character editing tools are complex and non-intuitive. It takes lot of skill and labor from the artists to create even a draft 3D humanoid model. This paper proposes an intuitive 2D sketch-driven drafting tool that allows users to quickly shape and proportion existing detailed 3D models. We leverage on our existing vector shape representation to describe character bodypart segments as affine-transformed circle-triangle-square shape blends. This is done for both the input 2D doodle as well as for the extracted point clouds from 3D library mesh. The simplified body part vector shapes help describe the relative deformation between the source (3D library mesh) and the target (2D frontal sketch). The actual deformation is done using automatically setup Free Form Deformation cages. To perform body-part shape analysis, we first segment the mesh with Baran and Popovic's algorithm for automatic fitting of an input skeleton to a given 3D mesh, followed by our existing 2D shape vector fitting process. There are several promising character design applications of this paper; e.g. accelerated personality pre-visualization in movie production houses, intuitive customization of avatars in games and interactive media, and procedural character generation.

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