This paper addresses the problem of rigid motion estimation and 3D reconstruction in vision systems where it is possible to recover the incident direction from image points. Such systems include pinhole cameras and catadioptric cameras. Given two images of the same scene acquired from two positions, the transformation is estimated by means of an iterative process. The estimation process aims at having corresponding incident rays intersecting at the same 3D point. Geometrical relationships are derived to support the estimation method. Experiments with real images are presented.