Georgia State University ScholarWorks @ Georgia State University Computer Science Dissertations Department of Computer Science 12-4-2006 A Framework for Dynamic Terrain with Application in Off-road Ground Vehicle Simulations Anthony Scott Aquilio Follow this and additional works at: https://scholarworks.gsu.edu/cs_diss Part of the Computer Sciences Commons Recommended Citation Aquilio, Anthony Scott, "A Framework for Dynamic Terrain with Application in Off-road Ground Vehicle Simulations." Dissertation, Georgia State University, 2006. https://scholarworks.gsu.edu/cs_diss/11 This Dissertation is brought to you for free and open access by the Department of Computer Science at ScholarWorks @ Georgia State University. It has been accepted for inclusion in Computer Science Dissertations by an authorized administrator of ScholarWorks @ Georgia State University. For more information, please contact [email protected]. A FRAMEWORK FOR DYNAMIC TERRAIN WITH APPLICATION IN OFF-ROAD GROUND VEHICLE SIMULATIONS by ANTHONY S. AQUILIO Under the Direction of Ying Zhu and G. Scott Owen ABSTRACT The dissertation develops a framework for the visualization of dynamic terrains for use in interactive real-time 3D systems. Terrain visualization techniques may be classified as either static or dynamic. Static terrain solutions simulate rigid surface types exclusively; whereas dynamic solutions can also represent non-rigid surfaces. Systems that employ a static terrain approach lack realism due to their rigid nature. Disregarding the accurate representation of terrain surface interaction is rationalized because of the inherent difficulties associated with providing runtime dynamism. Nonetheless, dynamic terrain systems are a more correct solution because they allow the terrain database to be modified at run-time for the purpose of deforming the surface. Many established techniques in terrain visualization rely on invalid assumptions and weak computational models that hinder the use of dynamic terrain. Moreover, many existing techniques do not exploit the capabilities offered by current computer hardware. In this research, we present a component framework for terrain visualization that is useful in research, entertainment, and simulation systems. In addition, we present a novel method for deforming the terrain that can be used in real-time, interactive systems. The development of a component framework unifies disparate works under a single architecture. The high-level nature of the framework makes it flexible and adaptable for developing a variety of systems, independent of the static or dynamic nature of the solution. Currently, there are only a handful of documented deformation techniques and, in particular, none make explicit use of graphics hardware. The approach developed by this research offloads extra work to the graphics processing unit; in an effort to alleviate the overhead associated with deforming the terrain. Off-road ground vehicle simulation is used as an application domain to demonstrate the practical nature of the framework and the deformation technique. In order to realistically simulate terrain surface interactivity with the vehicle, the solution balances visual fidelity and speed. Accurately depicting terrain surface interactivity in off-road ground vehicle simulations improves visual realism; thereby, increasing the significance and worth of the application. Systems in academia, government, and commercial institutes can make use of the research findings to achieve the real-time display of interactive terrain surfaces. INDEX WORDS: Terrain visualization, Dynamic terrain, Vehicle visualization, Off-road simulation A FRAMEWORK FOR DYNAMIC TERRAIN WITH APPLICATION IN OFF-ROAD GROUND VEHICLE SIMULATIONS by ANTHONY S. AQUILIO A Dissertation Submitted in Partial Fulfillment of the Requirements for the Degree of Doctor of Philosophy in the College of Arts and Sciences Georgia State University 2006 Copyright by Anthony Scott Aquilio 2006 A FRAMEWORK FOR DYNAMIC TERRAIN WITH APPLICATION IN OFF-ROAD GROUND VEHICLE SIMULATIONS by ANTHONY S. AQUILIO Major Professor: Ying Zhu Major Professor: G. Scott Owen Committee: Yi Pan Yichuan Zhao Electronic Version Approved: Office of Graduate Studies College of Arts and Sciences Georgia State University December 2006 TABLE OF CONTENTS LIST OF TABLES ........................................................................................................... vi LIST OF FIGURES ........................................................................................................ vii 1. INTRODUCTION......................................................................................................... 1 1.1 SIGNIFICANCE ....................................................................................................................................... 1 1.2 MOTIVATION ........................................................................................................................................ 1 1.3 RESEARCH OBJECTIVE .......................................................................................................................... 6 1.4 CHALLENGES ........................................................................................................................................ 7 1.5 METHODOLOGY : VISUALIZING DYNAMIC TERRAIN IN OFF -ROAD CONDITIONS ................................. 10 1.6 CONTRIBUTION & RESULTS ................................................................................................................ 14 1.7 THESIS OVERVIEW .............................................................................................................................. 16 2. A COMPONENT FRAMEWORK FOR TERRAIN VISUALIZATION............. 19 2.1 INTRODUCTION ................................................................................................................................... 19 2.2 MODELING .......................................................................................................................................... 22 2.3 MODEL SERVICES ............................................................................................................................... 36 2.4 RENDERING ........................................................................................................................................ 40 2.5 ANIMATION ........................................................................................................................................ 46 2.6 APPLICATION LOGIC AND APPLICATION -SPECIFIC FEATURES ............................................................ 51 2.7 DATA FLOW THROUGH COMPONENTS ................................................................................................. 52 2.8 REVIEW .............................................................................................................................................. 56 3. SURVEY OF TERRAIN VISUALIZATION TECHNIQUES............................... 58 3.1 INTRODUCTION ................................................................................................................................... 58 3.2 SPATIAL PARTITIONING ...................................................................................................................... 58 3.3 TEXTURING ......................................................................................................................................... 64 3.4 LEVEL OF DETAIL ................................................................................................................................ 72 3.5 DYNAMIC TERRAIN ........................................................................................................................... 106 3.6 CLOSING ........................................................................................................................................... 118 4. TECHNIQUES FOR DYNAMIC TERRAIN ........................................................ 119 4.1 DYNAMIC EXTENSION TO RESOLUTION ............................................................................................ 120 4.2 DYNAMICALLY DIVISIBLE REGIONS ................................................................................................. 121 iv 4.3 TERRAIN DYNAMISM ........................................................................................................................ 136 4.4 TERRAIN DYNAMISM ON THE GPU................................................................................................... 142 4.5 LARGE TERRAINS AND DYNAMISM ................................................................................................... 154 4.6 CLOSING ........................................................................................................................................... 157 5. DYNAMIC TERRAIN SYSTEM............................................................................ 159 5.1 INTRODUCTION ................................................................................................................................. 159 5.2 GOALS .............................................................................................................................................. 159 5.3 SYSTEM DESIGN ............................................................................................................................... 160 5.4 COMPONENT DESIGN .......................................................................................................................