1. A method of augmenting a first stereoscopic image comprising a pair of images, the method comprising the steps of: generating, by one or more processors, a disparity map from the pair of images of the first stereoscopic image, the disparity map being indicative of distances in the first stereoscopic image; generating a virtual three-dimensional model comprising a mesh based upon the distances indicated by the disparity map; modelling, by the one or more processors, an interaction of a virtual object with the three dimensional model, in which the virtual object has a physical attribute associated with it, and the interaction of the virtual object with the three dimensional model utilises the physical attribute; and outputting, for display, an image corresponding to the first stereoscopic image that comprises a visible effect of the interaction of the virtual object with the three dimensional model.