Software takes the virtual track to safety

Tom Shelley reports on how real world filming enhances virtual reality design for railways.

Virtual reality technology developed for use in Hollywood Films is being used to design railway signalling systems. The idea, which allows drivers to see track and signals clearly and unambiguously, could equally well be applied to improving design in truly realistic driving, operating and maintenance scenarios. The breakthrough achieved by Kent company Gioconda is the total integration of high-definition video and CAD modelling to allow virtual reality design to be undertaken in a real world simulation in real time. The development started when Network Rail asked Giaconda to come up with a virtual reality way of assessing sites for signals that did not require site visits by signal sighting committees. Not only do these take up a lot of time, but they are also associated with a certain amount of hazard, because trains are not stopped to allow them to take place. The footage is annotated and used to survey and plan asset recovery and installation. Tools developed by Giaconda allow 3D CAD models of signals to be imposed on video sequences, and their dimensions, orientation and type of beams amended to ensure maximum visibility and to prevent confusion between signals relating to different parallel sections of track. Positions are directly related to CAD drawings of track layouts, which are precisely related to the video sequences. 3D OLE and other structures can be placed on the video footage to assess the effect of obstructions. Existing signals that are to be removed can be blurred out, but not deleted. Alternatively, track, signals and everything else can be created from scratch in a virtual world. Having completed the signalling design, the new virtual railway can be used for driver training and route familiarisation. As well as railways, there are many other instances where this kind of approach could be useful. Virtual reality is widely used to assess car and aircraft cockpit design and maintenance scenarios for everything from engines to nuclear reactors. It would be most useful to integrate real world video into some of the processes to improve realism, especially modification of CAD designs within a realistic environment. The only problem is that the real world camera can only move along certain paths, but this should not be too serious a limitation when applied to aircraft landing, driving and plunging into machinery along predetermined paths for maintenance. To allow for deviations, it is possible to shoot the video at a wider angle than that viewed on the screen at any one time so the user can move sideways within the captured scenes. Such techniques are already used in gaming, which has for some time been at the leading edge when it comes to realistic simulation.