AMPHIBIOUS OPERATIONS IN A VIRTRUAL ENVIRONMENT by Didier A . Le Goff March 1997

Public reporting burden for this collection of information is estimated to average 1 hour per response, including the time reviewing instructions, searching existing data sources gathering and maintaining the data needed, and completing and reviewing the collection of information. Send comments regarding this burden estimate or any other aspect of this collection of information, including suggestions for reducing this burden The views expressed in this thesis are those of the authors and do not reflect the official policy or position of the Department of Defense or the United States Government. Approved for public release; distribution is unlimited. More than 80 percent of recent, real world, naval operations have taken place in the littoral; over half have employed amphibious units. However, up till now, no simulation developed at the Naval Postgraduate School had the capability to exercise any type of naval amphibious operation. Previous simulations lacked the necessary amphibious ship and landing craft models. Second, a method for nesting mounted entities did not exist. The approach taken was to develop a general algorithm for dynamically mounting, unmounting and nesting entities. Secondly, amphibious ship and landing craft models were developed incorporating a simple hydrodynamic models for use with the LPD-17 and Landing Craft Air Cushion (LCAC) vehicles. Finally, real-time collision detection was implemented to ensure realistic interaction between all entities. The result is a stand-alone, 3-D, virtual environment (VE) which simulates landing craft embarkation operations between a mother ship (LPD-17 class) and an LCAC, and allows embarked entities to walk through the 50,000 polygon LPD model in real-time (7-15 frames per second). The simulation is further enhanced by realistic wave response, based on the Pierson-Moskowitz spectrum, by all ocean borne vehicles. Lastly, the use of the high level EasyScene 3.0 API allowed the application to be written in approximately 30 percent few lines of code than otherwise possible. ii iii Approved for public release; distribution is unlimited. iv v ABSRACT More than 80 percent of recent, real world, naval operations have taken place in the littoral; over half have employed amphibious units. However, up till now, no simulation developed at the Naval Postgraduate School had the capability to exercise any type of naval amphibious operation. Previous simulations lacked the necessary amphibious ship and landing craft models. Second, a method for nesting mounted entities did not exist. The approach taken was to develop a general algorithm for dynamically mounting, unmounting and nesting entities. …