Wenger, StephanLorenz, DirkMagnor, MarcusB. Levy, X. Tong, and K. Yin2015-02-282015-02-2820131467-8659https://doi.org/10.1111/cgf.12216Astronomical nebulae are among the most complex and visually appealing phenomena known outside the bounds of the Solar System. However, our fixed vantage point on Earth limits us to a single known view of these objects, and their intricate volumetric structure cannot be recovered directly. Recent approaches to reconstructing a volumetric 3D model use the approximate symmetry inherent to many nebulae, but require several hours of computation time on large multi-GPU clusters. We present a novel reconstruction algorithm based on group sparsity that reaches or even exceeds the quality of prior results while taking only a fraction of the time on a conventional desktop PC, thereby enabling end users in planetariums or educational facilities to produce high-quality content without expensive hardware or manual modeling. In principle, our approach can be generalized to other transparent phenomena with arbitrary types of user-specified symmetries.I.3.8 [Computer Graphics]ApplicationsJ.2 [Computer Applications]Physical Sciences and EngineeringAstronomy