1. A computer implemented method of fitting a plane for a three-dimensional model, the model comprising vertices interconnected by line segments, the plane and model being represented by data in computer memory, the method comprising: accessing: a collection of digital photos and a cloud of points, where the photos are of a real world scene, where the photos are three-dimensionally arranged in a three-dimensional space containing the three-dimensional model, where the points are also arranged in the three-dimensional space, and where each point in the cloud corresponds to a feature of the scene that exists in at least two of the photos; receiving information identifying a plurality of points corresponding to a first photo in the collection of photos; obtaining a vanishing direction in the three-dimensional space by analyzing the first photo to identify a corresponding vanishing point of the scene in the first photo, and using the vanishing point and the orientation of the photo in the three-dimensional space to compute the vanishing direction; arranging the plane in the three-dimensional space by fitting the plane to at least the vanishing direction and/or at least one of the points in the plurality of points; and displaying a rendering of the model according to the fitted plane.