A method of augmenting a first stereoscopic image comprising a pair of images, the method comprising the steps of: generating a disparity map from the pair of images of the first stereoscopic image, the disparity map being indicative of distances between the camera and surfaces in the first stereoscopic image; - defining a series of value ranges corresponding to disparity values of the disparity map, each value range in the series having a starting point and an end point, said end point corresponding to a greater disparity than the end point of preceding value ranges in the series; - selecting points in the disparity map falling within the respective value range; - generating a respective mesh responsive to those selected points; and - sequentially merging the resulting series of generated meshes to form the three dimensional model of the scene. generating at least a first texture from one or both of the pair of images of the stereoscopic image; applying the texture to at least a respective part of the three dimensional model; modelling an interaction of a virtual object with that three dimensional model, in which the virtual object comprises a light source, and the textured three dimensional model is rendered illuminated responsive to that light source; 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. generating a disparity map from the pair of images of the first stereoscopic image, the disparity map being indicative of distances between the camera and surfaces in the first stereoscopic image; - defining a series of value ranges corresponding to disparity values of the disparity map, each value range in the series having a starting point and an end point, said end point corresponding to a greater disparity than the end point of preceding value ranges in the series; - selecting points in the disparity map falling within the respective value range; - generating a respective mesh responsive to those selected points; and - sequentially merging the resulting series of generated meshes to form the three dimensional model of the scene. generating at least a first texture from one or both of the pair of images of the stereoscopic image; - defining a series of value ranges corresponding to disparity values of the disparity map, each value range in the series having a starting point and an end point, said end point corresponding to a greater disparity than the end point of preceding value ranges in the series; - selecting points in the disparity map falling within the respective value range; - generating a respective mesh responsive to those selected points; and - sequentially merging the resulting series of generated meshes to form the three dimensional model of the scene. applying the texture to at least a respective part of the three dimensional model; modelling an interaction of a virtual object with that three dimensional model, in which the virtual object comprises a light source, and the textured three dimensional model is rendered illuminated responsive to that light source; 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.