Real-time Skeletal Skinning with Optimized Centers of Rotation

摘要

Skinning algorithms that work across a broad range of character de-rnsigns and poses are crucial to creating compelling animations. Cur-rnrently, linear blend skinning (LBS) and dual quaternion skinningrn(DQS) are the most widely used, especially for real-time applica-rntions. Both techniques are efficient to compute and are effective forrnmany purposes. However, they also have many well-known arti-rnfacts, such as collapsing elbows, candy wrapper twists, and bulgingrnaround the joints. Due to the popularity of LBS and DQS, it wouldrnbe of great benefit to reduce these artifacts without changing the an-rnimation pipeline or increasing the computational cost significantly.rnIn this paper, we introduce a new direct skinning method that ad-rndresses this problem. Our key idea is to pre-compute the optimizedrncenter of rotation for each vertex from the rest pose and skinningrnweights. At runtime, these centers of rotation are used to interpo-rnlate the rigid transformation for each vertex. Compared to otherrndirect skinning methods, our method significantly reduces the ar-rntifacts of LBS and DQS while maintaining real-time performancernand backwards compatibility with the animation pipeline.