Robust Human Animation Skeleton Extraction Using Compatibility and Correctness Constraints

The ability to automatically animate arbitrary 3D characters based on motion capture (MoCap) data has many applications in simulation, entertainment and multimedia transmission. However, defining trajectory key-points in human figures for animation without any manual intervention remains a challenging problem that makes complete automation difficult. To animate an articulated 3D character an animation skeleton needs to be extracted from, or be embedded into, a 3D model for deformation during animation. In conventional animation software, this process is mostly done manually by expert animators, which makes it a very tedious and time consuming step. The automatic rigging approaches proposed in the literature require a front facing model with neutral T-pose to accurately extract or embed an animation skeleton. We propose a fully automatic skeleton extraction approach based on optimization of constraints on human shape that can generate the animation skeleton, regardless of the model's orientation and position. Experimental results demonstrate the effectiveness of our approach. Robust skeleton extraction followed by efficient MoCap data compression can greatly improve the fidelity of 3D animated model transmission.