1. A method comprising: receiving a sequence of images of a scene taken by a camera, the scene having a scene geometry; identifying one or more two-dimensional features that appear in each of the images in the sequence of images; associating a respective three-dimensional point in a three-dimensional space with each of the identified two-dimensional features, each three-dimensional point being a point that represents no prior known position in the scene, the three-dimensional space having no prior known relationship to the scene geometry; tracking each of the two-dimensional features through successive images in the sequence of images; and determining a three-dimensional position of the camera in the three-dimensional space solely by iteratively minimizing a two-dimensional image error between the tracked two-dimensional features and an image reprojection of each of the three-dimensional points.