Skinning with dual quaternions

Abstract

Figure 1: A comparison of dual quaternion skinning with previous methods: log-matrix blending [Cordier and Magnenat-Thalmann 2005] and spherical blend skinning [Kavan and Zara 2005]. The proposed approach not only eliminates artifacts, but is also much easier to implement and more than twice as fast. AbstractSkinning 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 paper, we present a novel GPU-friendly skinning algorithm based on dual quaternions. We show that this approach solves the artifacts of linear blend skinning at minimal additional cost. Upgrading an existing animation system (e.g., in a videogame) from linear to dual quaternion skinning is very easy and has negligible impact on run-time performance.

Simple Flexible Skinning Based on Manifold Modeling

“…In all cases the Dual Quaternion technique (Kavan et al, 2007) was used to deform the meshes. The segmentation pre-processing step is done in real-time, and so is done the weight computation.…”

“…One of them is to Overlaps and weights were computed using a geodesic distance, and deformations were created using the technique of (Kavan et al, 2007).…”

“…Recently, Rohmer et al proposed a local volume preservation technique which enables the creation of both rubber-like and realistic deformations for organic shapes, depending on the correction map applied to skinning weights (Rohmer et al, 2008). The solution we suggest is more flexible in the sense that any deformation, from quasi-rigid to soft, can be created, and any skinning method can be used: for instance LBS, (Merry et al, 2006;Kavan et al, 2007). It also lies in the general (rigid) skeleton-based animation framework, and do not need the creation of new tools such as spline curves.…”

Frame-Based Interactive Simulation of Complex Deformable Objects

“…Another solution, is to use a better blending function. For rigid frames, dual quaternion blending offers a good approximation of the linear interpolation of screws at a reasonable computational cost [20]. It provides a closed-form solution for more than two transforms contrary to screw interpolation that requires an iterative treatment.…”

“…Finally the blended dual quaternion is converted [20] into a 3 × 4 rigid transformation matrix A to transform material points: u = Ap * −p. The displacement u of a deformable object is discretized using nodes (blue).…”