Global Registration of Dynamic Range Scans for Articulated Model Reconstruction

We present the articulated global registration algorithm to reconstruct articulated 3D models from dynamic range scan sequences. This new algorithm aligns multiple range scans simultaneously to reconstruct a full 3D model from the geometry of these scans. Unlike other methods, we express the surface motion in terms of a reduced deformable model and solve for joints and skinning weights. This allows a user to interactively manipulate the reconstructed 3D model to create new animations. We express the global registration as an optimization of both the alignment of the range scans and the articulated structure of the model. We employ a graph-based representation for the skinning weights that successfully handles difficult topological cases well. Joints between parts are estimated automatically and are used in the optimization to preserve the connectivity between parts. The algorithm also robustly handles difficult cases where parts suddenly disappear or reappear in the range scans. The global registration produces a more accurate registration compared to a sequential registration approach, because it estimates the articulated structure based on the motion observed in all input frames. We show that we can automatically reconstruct a variety of articulated models without the use of markers, user-placed correspondences, segmentation, or template model.