Dynamic Terrain A Dynamic Terrain is the representation of terrain ( e . g . mountains , hills , valleys ) together with the capability for modification during a simulation ( e . g . a constructive soldier ( i . e . battlespace entity ) digging a trench ) . Dynamic Terrain in Military Simulation . Dynamic terrain has been supported in military training simulations since the mid - 1990s in the Close Combat Tactical Trainer ( CCTT ) , the first trainer in the Combined Arms Tactical Trainer ( CATT ) family of military training systems . At the time , the Institute for Simulation and Training ( IST ) at the University of Central Florida ( UCF ) had been researching the dynamic terrain requirements of networked military simulations , including excavation , clouds and other atmospheric events , and water flow . The complexity proposed by IST was computationally expensive and not practical for the technology available at that time . Therefore , CCTT implemented dynamic terrain events as " dynamically placed features " ( DPFs ) that described the terrain deformation , such as a " tank ditch " . Tank ditches are either 30 , 60 , 90 , or 120 meters long and may be oriented in three dimensions . Since CCTT represents the terrain as an equally spaced elevation grid , terrain reasoning queries are adjusted based on the presence of a DPF . Nevertheless , the dynamic terrain implementation in CCTT caused a mismatch between the CCTT Semi - Automated Forces ( SAF ) and the visual display . The SAF reasons on the terrain and feature geometry , whereas the visual display focuses on presenting the terrain as a realistic scene . The difference between these two representations of the terrain is similar to the difference between " feeling " and " seeing " , therefore these representations store information in very different ways . In the late 1990s , the Synthetic Theater of War ( STOW ) effort sponsored by the Defense Advanced Research Projects Agency ( DARPA ) provided the capability to communicate and apply terrain deformations but the implementation still required high - end platforms without satisfying real - time requirements . The Dynamic Terrain Simulator ( DTSim ) was developed for the STOW Synthetic Environments ( SE ) program at the United States Army Corps of Engineers Army Geospatial Center ( ASG ) ( formerly Topographic Engineering Center ( TEC ) ) . Other applications reused the DTSim framework for more specific implementations of the dynamic terrain capabilities , for example RunwaySim , the Hydrogeologic Simulator ( HydroSim ) , Dynamic Terrain Scribe ( DTScribe ) , Dynamic Terrain Agent ( DTAgent ) , and the Ultra - High Resolution Building Simulator ( UHRB - Sim ) In 2003 , the U . S . Army Research Laboratory ( ARL ) released documentation related to their Dynamic Terrain Server ( DTServer ) . DTServer computes structural effects of detonations and collisions and transmits the result to client simulations , making sure that all simulators share a unified terrain database . DTServer also uses a table look - up to compute the effects of blasts and collisions . The DTServer provides terrain updates by issuing distributed interactive simulation ( DIS ) protocol data units ( PDUs ) . DTServer sends DIS Set Data PDUs of the following types : Breach Subtract , Breach vertices , and Ding messages . DTServer also provides a graphical user interface ( GUI ) to inspect the state of the database . DTServer runs on three different databases : the terrain database , the object database , and the munitions database . The DIS interface has been successfully tested in the Soldier Visualization System ( SVS ) , the After Action Review ( AAR ) system from IST , and the ARL DIS . There are current efforts to include dynamic terrain capabilities in One Semi - Automated Forces ( OneSAF ) . The OneSAF Environment Runtime Component ( ERC ) updates presented in the 2009 OneSAF Users Conference mention that OneSAF 4 . 0 will include support for terrain deformation such as craters , tank defilades , infantry trenches , and breach holes in walls . OneSAF ' s dynamic terrain implementation will use a server to resolve dynamic terrain requests . The U . S . Army Research , Development , and Engineering Command ( RDECOM ) Simulation and Training Technology Center ( STTC ) is sponsoring the development of the Shared Architecture for Dynamic Environment ( SHADE ) . SHADE will provide a framework to receive events , calculate effects , and transmit dynamic environment changes to participating applications . These efforts will seek to address the dynamic terrain capability gap in modeling and simulation identified by the U . S . Army Training And Doctrine Command ( TRADOC ) Intelligence Support Activity ( TRISA ) .