NTT Systems developed the second major version of the Leopard Tank Video Interactive Gunnery Simulator (LVIGS) for the Simulation Group at DCIEM. The first version was an Advanced Development Model (ADM) developed by Bendix Avelex which never went into production. This was implemented on an IBM 80286 based PC, using a Pioneer video disk player as the image source and performing image manipulation with a combination of a Matrox MVP and VGO cards. NTT Systems developed a modified version of the ADM, implementing pop up targets as a training aid for the 1991 Canadian Army Trophy competition in Germany. Most of the work needed to perform this task was done on a Commodore AMIGA computer which modified the video disk image on route to the PC. Consequently very few changes were needed in the ADM.
The current version of LVIGS was developed in response to DCIEM's need for:
A modular and generic VIGS which could be used as the base for a variety of weapon systems.
Enhancing the VIGS concept through the support of multiple simulators which could interact through a data network.
These requirements in conjunction with technology advances since the development of the ADM supported a decision to redevelop the software on a new platform.
The implementation was developed in C++ on a 486 PC. The Matrox Illuminator Pro video card was selected as the video manipulation device. At the time of evaluation, it was the only one that would support the real time frame capture, zoom, pan and scroll requirements of the application.
The LVIGS simulator allows the student to pan and scroll the sight in a visual field by using the power control on the weapons console. This allows the simulator display to appear as a window onto an external world four times as large. The video image is delivered from laserdisc, with the graticule and computer generated pop-up targets overlaid on top.
In LVIGS, the world consists of a 3D space visible to a number of simulators positioned on a straight horizontal line. Typically there is a significant amount of visual overlap between pairs of simulators. This world contains a base plane, terrain features (hills and valleys), obstacles, and targets.
Terrain features are used to model hills and valleys. Each feature is defined by a series of vertical lines which mark its bottom and top at significant cross range locations. Each marker has a front and back range associated with it so that the features can have slope. This allows for accurate display of shell landings on hillsides. Terrain features are implemented by \className{clslvigsTerrainObject}.
Obstacles are similar to terrain objects except that they do not have a slope, they can each have a different laser reflectivity and they can be either hard or soft (i.e., shells explode on them or pass through them). Targets are a kind of obstacle. They can appear and disappear, and they can move.
The simulator has this whole 3D world modelled internally, and overlaid on a 2D video image. So the internal 3D model of a hill will correspond with the 2D hill viewed in the simulator's display. When the student fires a shell, a 3D landing location is computed, and if it is a hit, an explosion is displayed.
Once a student begins a mission on the simulator, output is provided to the instructor, identifying key events such as lasing, ammunition selection, firing, hits, misses, et cetera. A Nexpert interface is available to the instructor, which will provide assistance regarding the student's performance.
The LVIGS simulator is designed to support multiple VIGS simulators with overlapping visual spaces. Communication services are required to provide all VIGS with mission information, to synchronize the start of the mission, and to share shell landing information.
The Mission Editor is a standalone program used to create and edit VIGS missions. This process involves specifying things like locations of terrain objects, obstacles and targets, and defining the camera movement that takes place over the course of the mission.