In distributed simulation systems, there has been no capability to modify the terrain surface during the course of a simulation exercise, which is necessary for emplacing and breaching obstacles such as anti-tank ditches, road craters and rubble. Current distributed simulation exercises are restricted to static terrain databases and low fidelity environmental phenomena, limiting the value of training, system evaluation and mission rehearsal. Changing the here-tofore static database at run-time has been a significant technical challenge. The Synthetic Theatre of War (STOW) program requires the ability to emplace and breach obstacles, bomb airfields to create craters, and destroy interdiction targets. The Dynamic Terrain and Objects (DTO) program is developing this technology. Sponsored by DARPA and the U.S. Army Topographic Engineering Center (TEC), this technology provides a long term foundation for dynamic terrain and object interaction in the virtual world.

This paper provides an overview of the DTO effort including operational requirements analysis, system architecture, and the implementation providing changes to the physical environment in distributed simulation systems. The definition of battlefield activities which change the terrain surface serves to identify and prioritize DTO goals in areas including mobility/countermobility, sustainment, survivability, seasonal changes, and terrain changes resulting from combat activities.

The DTO architecture fully distributes the ability to make changes includes three major components: the DT Simulator, DT Scribe, and DT Agent. Changes are distributed via messages called Environmental Change Notices (ECN). DT Simulators such as the Combat Engineer Workstation transmit change request to the DT Scribe. DT Scribes maintain consistency and reliability of the simulation by serializing and arbitrating changes. DT Agents transform the ECNs into the run-time data bases of their clients.

DTO capabilities have been demonstrated and implemented within the computer generated forces system ModSAF and the Vistaworks ModStealth in distributed simulation exercises. The DTO architecture has been developed to ensure portability to other systems by use of standard application programming interfaces and reusable libraries.