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NPS ARCHIVE 1397. OS POSTGRADUATE SCHOOL Lb GOFF, D. Monterey, California THESIS AMPHIBIOUS OPERATIONS IN A VIRTRUAL ENVIRONMENT by DidierA. Le Goff March 1997 Thesis Advisor: Michael J. Zyda Thesis Co-Advisor: John S. Falby Approved forpublic release; distribution is unlimited. Thesis L46453 DUDLEYKNOXLIBRARY NAVAL POSTGRADUATESCHOOL MONTEREY CA 93943-5101 REPORT DOCUMENTATION PAGE FormApproved OMBNo. 0704-0188 Publicreportingburdenforthiscollectionofinformationisestimatedtoaverage1hourperresponse,includingthetimereviewinginstructions,searchingexistingdatasources gatheringandmaintainingthedataneeded,andcompletingandreviewingthecollectionofinformation.Sendcommentsregardingthisburdenestimateoranyotheraspectofthis collectionofinformation,includingsuggestionsforreducingthisburdentoWashingtonHeadquartersServices,DirectorateforInformationOperationsandReports,1215Jefferson DavisHighway,Suite1204,Arlington,VA22202-4302,andtotheOfficeofManagementandBudget.PaperworkReductionProject(0704-0188),Washington,DC20503. 1.AGENCYUSEONLY(LeaveBlank) 2.REPORTDATE 13.REPORTTYPEANDDATESCOVERED March 1997 Master's Thesis I 4.TITLEANDSUBTITLE 5. FUNDINGNUMBERS Amphibious Operations in a Virtual Environment. 6.AUTHOR(S) Le Goff, Didier, A. 7.PERFORMINGORGANIZATIONNAME(S)ANDADDRESS(ES) 8.PERFORMINGORGANIZATION Naval Postgraduate School REPORTNUMBER Monterey, CA 93943-5000 9.SPONSORING/MONITORINGAGENCYNAME(S)ANDADDRESS(ES) 10.SPONSORING/MONITORING AGENCYREPORTNUMBER 11.SUPPLEMENTARYNOTES The views expressed in this thesis are those ofthe authors and do not reflect the official policy orposition ofthe Department ofDefense or the United States Government. 12a.DISTRIBUTION/AVAILABILITYSTATEMENT 12b.DISTRIBUTIONCODE Approved forpublic release; distribution is unlimited. 13.ABSTRACT(Maximum200words) More than 80percentofrecent, real world, naval operations have taken placein thelittoral; overhalfhaveemployed amphibiousunits.However,uptillnow,nosimulationdevelopedattheNavalPostgraduateSchoolhadthecapabilitytoexercise any typeofnaval amphibiousoperation. Previous simulationslackedthe necessary amphibious shipandlandingcraftmodels. Second, amethod fornesting mountedentities did notexist. Theapproachtaken wastodevelopageneral algorithm fordynamically mounting, unmounting andnestingentities. Secondly,amphibiousshipandlandingcraftmodelsweredevelopedincorporatingasimplehydrodynamicmodelsforusewith theLPD-17 andLandingCraftAirCushion (LCAC) vehicles. Finally, real-timecollision detection was implementedtoensurerealistic interactionbetween all entities. The resultis astand-alone, 3-D, virtual environment(VE) whichsimulates landingcraftembarkation operations betweena mothership (LPD-17 class) andan LCAC, andallowsembarkedentities to walkthroughthe 50,000polygonLPDmodel in real-time (7-15 frames persecond). Thesimulation is furtherenhanced by realistic waveresponse, based on the Pierson- Moskowitzspectrum, by all oceanbomevehicles. Lastly, theuseofthehighlevelEasyScene3.0APIallowedtheapplication tobewritten in approximately 30percentfew lines ofcodethan otherwisepossible. 14.SUBJECTTERMS 15.NUMBEROFPAGES NPSNET, Easy Scene, real-time, 3D, visual simulation, Performer, 88 interactive, virtual world, PVS, Potentially Visible Sets, mounting humans 16.PRICECODE entities, ocean model, tool kit. 17.SECURITYCLASSIFICATION 18.SECURITYCLASSIFICATION 19.SECURITYCLASSIFICATION 20.LIMITATIONOFABSTRACT OFREPORT OFTHISPAGE OFABSTRACT UL Unclassified Unclassified Unclassified NSN7540-01-280-5500 StandardForm 298 (Rev. 2-89) PrescribedbyANSIStd.239-18 11 Approvedforpublic release; distributionisunlimited. AMPHIBIOUS OPERATIONS IN A VIRTUAL ENVIRONMENT Didier A. Le Goff Lieutenant, United States Navy B.A., Northwestern University, 1988 Submitted in partial fulfillment ofthe requirements for the degree of MASTER OF SCIENCE IN COMPUTER SCIENCE from the NAVAL POSTGRADUATE SCHOOL March 1997 DUDLEYKNOXLIBRARY NAVAL POSTGRADUATE SCHOO, MONTEREY CA 93943-5^ °L ABSRACT More than 80 percent ofrecent, real world, naval operations have taken place in the littoral; over half have employed amphibious units. However, up till now, no simulation developedatthe NavalPostgraduate Schoolhadthecapabilityto exercise anytype ofnaval amphibious operation. Previous simulations lacked the necessary amphibious ship and landing craft models. Second, a method fornesting mounted entities did not exist. The approach taken was to develop a general algorithm for dynamically mounting, unmounting and nesting entities. Secondly, amphibious ship andlandingcraftmodels were developed incorporating a simple hydrodynamic model 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 walkthrough 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 levelEasyScene 3.0API allowedthe applicationto be writtenin approximately 30 percent few lines ofcode than otherwise possible. VI TABLE OF CONTENTS INTRODUCTION I. 1 BACKGROUND A. 1 NPSNET 1. 1 2. Shiphandling Training Simulator 2 3. Damage Control Virtual EnvironmentTrainer 2 4. Mounted Networked Human Entities 2 MOTIVATION B. 3 1. Diminished Training Opportunities 3 2. Applying Virtual Reality 4 C. OBJECTIVE 5 APPROACH D. 6 E. SUMMARY OF CHAPTERS 7 II. PREVIOUS RESEARCH 9 A. SHIPHANDLING TRAINING SIMULATOR 9 B. DAMAGE CONTROL VIRTUALENVIRONMENT TRAINER 10 C. MOUNTED NETWORKED HUMAN ENTITIES 16 m. SOFTWARE ARCHITECTURE 19 BACKGROUND A. 19 High Speed Rendering 19 1. 2. Additional Functionality 20 3. NEXTGEN and NPSNET V 20 B. IRIS PERFORMER API 21 1. Multiprocessing 21 2. Hierarchical Database 23 C. EASYSCENE 3.0 API 25 1. Structure 25 2. Run-time Interface 28 Vll SUMMARY D. 30 EASYSCENE MARITIME MODULE IV. 3.0 33 INTRODUCTION A. 33 OCEAN MODEL B. 33 OCEAN SPECTRA C. 35 D. esSeaCONTRUCTION 36 SUMMARY E. 37 V. COLLISION DETECTION 39 A. INTERSECTION TESTING 39 1. Basic Mechanics 39 2. RunTime 41 B. INTERSECTION AND COLLISION MASKS 42 C. IMPLEMENTATION 43 LPD 44 1. 2. LCAC 44 3. Human 45 D. CONCLUSION 47 VI. MOUNTING ENTITIES 49 A. INTRODUCTION 49 B. DIS RESTRICTIONS 50 MOUNTING ALGORITHM C. 51 D. CONCLUSION 54 VE. MODELS 57 A. INTRODUCTION 57 1. LPD-17 57 2. Scenes from the Amphibious Simulator 59 VIE. CONCLUSION 63 A. RESULTS 63 FUTUREWORK B. 64 Vlll