3D reconstruction of scenes from image data is a classic problem in computer vision. Interest in this problem is at an all-time high, thanks to a wealth of applications which impact society in powerful ways---augmented reality, autonomous driving, cultural heritage, localization, mapping, and space exploration, to name a few. Some of these applications demand reliability of 3D reconstructions, e.g., for human safety, which translates to difficult and unsolved problems in mathematics. Other applications require efficiency at an ever-increasing scale, which calls for novelty in computational methods. This workshop will bring together experts working at an exciting crossroads where engineering, geometry, and optimization impact 3D reconstruction.