Keynote 1: Anatomically-Based Hand Simulation

I will present the multi-year efforts on modeling and animating human hands, performed in my laboratory at USC. Hands are important in many applications, such as computer games, film, ergonomic design, tracking, and medical treatment. I will discuss how to acquire complete human hand anatomy in multiple poses using magnetic resonance imaging (MRI). Acquiring human hand anatomy in multiple poses was previously difficult because MRI scans must be long for high-precision results (over 10 minutes), and because humans cannot hold their hands perfectly still in non-trivial and badly supported poses. We invented a manufacturing process whereby lifecasting materials commonly employed in film special effects industry are used to stabilize the hand during MRI scanning. We demonstrate how to efficiently segment the MRI scans into individual bone, muscle, tendon, ligament, fat and skin meshes in all poses, and how to correspond each organ’s mesh to the same mesh connectivity across all scanned poses. Next, we give a method to simulate the volumetric shape of the organs to any pose in the hand’s range of motion, producing both external skin shapes and internal organ shapes that match ground truth optical scans and medical images (MRI) in multiple scanned poses. We achieve this by combining MRI images in multiple hand poses with FEM multibody nonlinear elastoplastic simulation. This enables us to start with an arbitrary animation of the hand joint hierarchy, and produce a matching high-quality skin and internal organ animation of the hand. Our system models bones, muscles, tendons, ligaments and fat as separate volumetric organs that mechanically interact through contact and attachments, and whose shape matches medical images (MRI) in the MRI-scanned hand poses. We use our method to produce volumetric renders of the internal anatomy of the human hand in motion, and to compute and render highly realistic hand surface shapes.