A mechanism is provided for exploring three dimensional environments such as those generated from X-ray and tomography scans, in such a way as to "see round" obstacles to an article of interest, without degrading the overall context of an article of interest in terms of it position in relationship to other articles, and to the viewpoint of the user. This is achieved by defining a light guide curve leading to the user's viewpoint, with respect to which ray tracing is performed to define the image displayed to the user whereby rays passing within a predetermined distance of the light guide curve at a relative angle within a predetermined range thereto are deviated so as to conform therewith to a degree proportional to its distance therefrom.
