1. A method for determining poses of a camera relative to an environment, wherein the camera is movable, comprising: determining point correspondences from a set of initial images acquired of the environment by the camera; applying 2-point motion estimation to the point correspondences to determine a set of initial poses of the camera; and generating a point cloud from the set of initial poses and the point correspondences, and for each next image, performing the steps of: determining the point correspondences from the next image; determining the pose of the camera from the point correspondences of the next image and the point cloud; and updating the point cloud according to the pose and the point correspondences of the next image, wherein the steps are performed in a processor.