Hand Shadow Art: A Differentiable Rendering Perspective
This work addresses the problem of computational hand shadow art generation. We propose the first differentiable rendering-based method for 3D hand deformation inversion: given a target 2D shadow image and illumination conditions, it jointly optimizes the geometry and pose of both hands along with lighting parameters to minimize the discrepancy between rendered and target shadows. Our approach integrates neural implicit hand representations, physically grounded shadow modeling, and a gradient-guided co-optimization framework—enabling simultaneous bilateral hand solving and smooth pose interpolation across semantically distinct shadows. Experiments demonstrate stable reconstruction of high-fidelity hand shadows, precise matching of intricate shadow structures, and seamless temporal transitions. This work establishes a novel paradigm and practical toolkit for applying differentiable graphics to digital artistic creation.