Geometric skinning with approximate dual quaternion blending

Abstract

Skinning of skeletally deformable models is extensively used for real-time animation of characters, creatures and similar objects. The standard solution, linear blend skinning, has some serious drawbacks that require artist intervention. Therefore, a number of alternatives have been proposed in recent years. All of them successfully combat some of the artifacts, but none challenge the simplicity and efficiency of linear blend skinning. As a result, linear blend skinning is still the number one choice for the majority of developers. In this article, we present a novel skinning algorithm based on linear combination of dual quaternions. Even though our proposed method is approximate, it does not exhibit any of the artifacts inherent in previous methods and still permits an efficient GPU implementation. Upgrading an existing animation system from linear to dual quaternion skinning is very easy and has a relatively minor impact on runtime performance.

3D Character Animation: A Brief Review

“…To preserve the simplicity and speed of LBS and to solve the artifacts derived from the property of blending rotations, many researchers relied on mathematical tools (19)(20)(21)(22)(23). In kinematics the quaternion blending is widely used to blend the rotation matrix without the loss of algebraic property of SO (3) group (20).…”

Frame-Based Interactive Simulation of Complex Deformable Objects

“…To model deformable objects using a small number of control nodes, we need convenient, natural deformation functions. In character animation, the blending of frame displacements has been studied to deform a skin from an embedded articulated skeleton [21]. This method, called skinning or vertex blending or skeletal subspace deformation, is widely used, not only for its simplicity and efficiency, but because it provides natural and intuitive handles for controlling deformation.…”

Universally manipulable body models—dual quaternion representations in layered and dynamic MMCs

“…One possible extension of the quaternions is the dual quaternions (Clifford 1882; Kavan et al 2008;McCarthy 1990;Bottema and Roth 1979). Dual quaternions do not consist of real numbers, but instead use dual numbers.…”

“…The translation along the rotation axis is given by θ ε . s ε represents the position in space of the axis in an invariant way (this is called the moment, see Kavan et al 2008).…”