DexCap is a portable hand motion capture system that combines holography and electromagnetic field technology to provide accurate and occlusion-resistant wrist and finger motion tracking. It collects data by 3D observing the environment. The DexIL algorithm leverages inverse kinematics and point cloud-based imitation learning to directly train dexterous robotic hand skills from human hand movement data. The system supports optional human-in-the-loop calibration mechanisms, enabling the robotic hand to replicate human movements and further improve its performance based on human hand actions.