2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/136273Both in the plane and in space, we invert the nonlinear Ullman transformation for 3 points and 3 orthographic cameras. While Ullman's theorem assures a unique reconstruction modulo a reflection for 3 cameras and 4 points, we find a locally unique reconstruction for 3 cameras and 3 points. Explicit reconstruction formulas allow to decide whether picture data of three cameras seeing three points can be realized as a point-camera configuration.16 pages, 13 figuresComputer Vision and Pattern RecognitionArtificial IntelligenceI.2.10text