Interactive Web-Based Virtual Reality with Java 3D Chi Chung Ko National University of Singapore, Singapore Chang Dong Cheng National University of Singapore, Singapore InformatIon ScIence reference Hershey • New York ii Director of Editorial Content: Managing Development Editor: Senior Managing Editor: Managing Editor: Assistant Managing Editor: Copy Editor: Typesetter: Cover Design: Printed at: Kristin Klinger Kristin Roth Jennifer Neidig Jamie Snavely Carole Coulson Larissa Vinci Amanda Appicello Lisa Tosheff Yurchak Printing Inc Published in the United States of America by Information Science Reference (an imprint of IGI Global) 701 E Chocolate Avenue, Suite 200 Hershey PA 17033 Tel: 717-533-8845 Fax: 717-533-8661 E-mail: cust@igi-global.com Web site: http://www.igi-global.com/reference and in the United Kingdom by Information Science Reference (an imprint of IGI Global) Henrietta Street Covent Garden London WC2E 8LU Tel: 44 20 7240 0856 Fax: 44 20 7379 0609 Web site: http://www.eurospanbookstore.com Copyright © 2009 by IGI Global All rights reserved No part of this publication may be reproduced, stored or distributed in any form or by any means, electronic or mechanical, including photocopying, without written permission from the publisher Product or company names used in this set are for identification purposes only Inclusion of the names of the products or companies does not indicate a claim of ownership by IGI Global of the trademark or registered trademark Library of Congress Cataloging-in-Publication Data Ko, Chi Chung Interactive web-based virtual reality with Java 3D / by Chi Chung Ko and Chang Dong Cheng p cm Includes bibliographical references and index Summary: “This book provides both advanced and novice programmers with comprehensive, detailed coverage of all of the important issues in Java 3D” Provided by publisher ISBN 978-1-59904-789-8 (hardcover) ISBN 978-1-59904-791-1 (ebook) Java3D Java (Computer program language) Computer graphics Three-dimensional display systems Virtual reality I Cheng, Chang Dong II Title QA76.73.J38K595 2008 006.8 dc22 200800910 British Cataloguing in Publication Data A Cataloguing in Publication record for this book is available from the British Library All work contributed to this encyclopedia set is new, previously-unpublished material The views expressed in this encyclopedia set are those of the authors, but not necessarily of the publisher If a library purchased a print copy of this publication, please go to http://www.igi-global.com/agreement for information on activating the library's complimentary electronic access to this publication Table of Contents Preface ix Chapter I Virtual Reality and Java 3D Introduction Interactive 3D Computer Graphics Virtual Reality Web-Based Virtual Reality VRML Java 3D Mixed Reality 10 Summary 11 References 12 Chapter II Java 3D Overview 18 Introduction 18 Getting Started 19 A Simple Java 3D Program for a RotatingCube 20 Scene Graph Basics 22 Scene Graph for the RotatingCube 24 View Branch for the RotatingCube 25 Content Branch for the RotatingCube 26 Branch Group 27 Transform Group 28 Simple Universe 28 Difference Between Java 3D Applet and Application 29 Summary 30 References 30 v Chapter III Geometry Objects 32 Introduction 32 Shape3D 32 GeometryArray Class 35 GeometryStripArray 43 IndexedGeometryArray 56 IndexedStripArray 63 Creating an Object Using Multiple Geometry Classes 69 Utility Class 71 Summary 72 References 73 Chapter IV Appearance Objects 75 Introduction 75 PointAttributes 79 LineAttributes 82 PolygonAttributes 82 ColoringAttributes 86 TransparencyAttributes 87 RenderingAttributes 89 Material 93 Summary 95 References 96 Chapter V Textures 97 Introduction 97 Texture Loading 98 Texture Coordinates 99 Texture Properties 100 Texture Attributes 101 Texture Coordinate Generation 103 Multilevel Texturing 106 MultiTexture 106 Texture in Applets 110 Summary 112 References 112 Chapter VI Lighting, Fog, and Background 114 Introduction 114 Material 115 Ambient Light 117 Directional Light 118 Point Light 120 v Spot Light or Cone Light 122 Light Scopes 122 Fog 124 Background 128 Summary 130 References 130 Chapter VII Animation Objects 132 Introduction 132 Behavior and Animation 133 Alpha Object 133 Interpolator Object 134 PositionInterpolator 135 PositionPathInterpolator 136 RotationInterpolator 138 RotationPathInterpolator 138 RotPosPathInterpolator 140 ScaleInterpolator 142 RotPosScalePathInterpolator 143 SwitchValueInterpolator 144 TransparencyInterpolator 145 ColorInterpolator 146 Billboard 146 Level of Detail (LOD) 153 Morph 155 Summary 158 References 158 Chapter VIII Interaction 159 Introduction 159 Behavior Class 160 Bounding Region 163 Wakeup Condition and Criterion 165 Keyboard and Mouse Events 168 Posted Events 169 Collision Events 176 Elapsed Time and Frame Events 176 Events due to Changes in Positions and Transforms 180 Platform Entry and Exit Events 183 Sensor Entry and Exit Events 185 Combining Different Wakeup Criteria 185 Summary 186 References 186 v Chapter IX Picking 188 Introduction 188 PickRotateBehavior, PickTranslateBehavior, and PickZoomBehavior 189 Picking Classes in General 189 Customizing Picking Behavior Class 193 PickTool 194 Point and Ray Picking Shape 195 Ray Segment Picking Shape 196 Cone Picking Shape 201 Cylinder Picking Shape 206 Picking Objects within a Specified Bound from a Certain Position 209 Picking in a Virtual Instrument Panel 212 Summary 215 References 215 Chapter X Navigation, Input Devices, and Collision 217 Introduction 217 Keyboard Navigation Using KeyBoardBehavior 218 User Defined Keyboard Navigation 219 Navigation Using Mouse Utility Class 223 User-Defined Mouse Navigation 227 Input Device 229 Sensors 232 Collisions 234 Summary 236 References 237 Chapter XI Multiple Views 238 Introduction 238 View Model 239 Single View 240 Multiple Views 243 View Attach Policy and Activation Radius 245 Projection Policy 246 Clip Distance 248 Window Eyepoint Policy and Field of View 248 Conventional Camera-Based View 249 Visibility, Screen Scale, Window Movement, and Frame Cycle Time 252 Canvas3D 252 PhysicalBody and PhysicalEnvironment 258 Example Applications 260 Summary 263 References 263 v Chapter XII Audio 264 Introduction 264 BackgroundSound 265 PointSound 266 ConeSound 268 Aural Environment 269 Summary 273 References 275 Chapter XIII A Web-Based 3D Real Time Oscilloscope Experiment 276 Introduction 276 System Reference Model and Working Principle 279 Scene Graph and Main Applet 279 Control Buttons, Sliders, Knobs, and Other Objects 282 Custom Behavior 283 Navigation Behavior 284 Collision Detection Behavior 285 Picking Behavior 286 Summary 288 References 288 Appendix A Downloading Software 290 Appendix B Running the Rotating Cube Program 295 Appendix C ViewManager 301 Appendix D Main Applet for Web-Based 3D Experiment 308 Appendix E Scene Graph Implementation for Web-Based 3D Experiment 322 Appendix F Knob Class for Web-Based 3D Experiment 350 Appendix G Navigation and Collision Detection for Web-Based 3D Experiment 355 Appendix H Picking for Web-Based 3D Experiment 371 v Appendix I Program Summary and Screen Capture 441 About the Authors 469 Index 470 x Preface With the emergence of the Java 3D API, the creation of high quality 3D animated graphics for Java applications and applets has become a possibility Being a high-level API based on OpenGL and DirectX, Java 3D allows developers to produce object-oriented graphics applications that are platform-independent Numerous applications in fields ranging from business, science, medical to education have been implemented based on this technology One well known example is the Maestro project, which allows users to navigate the 3D world of Mars from a desktop computer based on inputs from eight 360-degree cameras onboard the rover In one of our research projects in this area, we have used Java 3D to develop a Web-based real time 3D oscilloscope experimentation system, which has been launched at National University of Singapore This application enables users to carry out a physical electronic experiment that involves the use of an actual oscilloscope, a signal generator, and a circuit board remotely through the Internet Specifically, the control of the various instruments are carried out in real time through the use of a Java 3D based interface on the client side, with the results of the experiment being also reflected or displayed appropriately on 3D instruments in the same interface In this application, Java 3D is used to create a virtual 3D world or room in which the 3D instruments reside The mouse is used for both navigation in this world as well as for operating the instruments through, say, dragging a sliding control or a rotary control or clicking or switching appropriate buttons on the instruments Associated commands that cause the real instruments in a remote physical laboratory to operate accordingly are then sent through the Internet in real-time Experimental results corresponding to, say, a change in the real oscilloscope display, are then sent from the instrument control server back to the Java 3D client to result in a real-time change in the display of the virtual 3D oscilloscope in the virtual 3D world Appendix I Chapter VII Page 144 Figure Code segment and result of RotPosScalePathInter java Chapter VII Page 145 Figure Code segment and result of DemoTransparency Interpolator.java Chapter VII Page 147 Figure 10 Code segment and result of DemoColor Interpolator.java Chapter VII Page 152 Figure 15 Fifth code segment and result of BillboardDemo java Chapter VII Page 155 Figure 18 Third code segment and result of LOD.java Copyright © 2009, IGI Global, distributing in print or electronic forms without written permission of IGI Global is prohibited Ko & Cheng Chapter VII Page 157 Figure 20 Morph behavior and result Chapter VIII Page 180 Figure 21 Code segment and result of WakeupOnElapsed TimeClock.java Chapter VII Page 182 Figure 24 Second code segment and result of TransformChange.java Chapter IX Page 188 Figure Illustration of picking behavior when the user picks and moves the cube Chapter IX Page 192 Figure Third code segment and result snapshoots for PickBehaviour.java Copyright © 2009, IGI Global, distributing in print or electronic forms without written permission of IGI Global is prohibited Appendix I Chapter IX Page 196 Figure Code segment and result for PickRayBehaviour.java Chapter IX Page 200 Figure 13 Result from PickSegmentBehavior java Chapter IX Page 201 Figure 14 Result from PickConeRayBehavior java Chapter IX Page 207 Figure 20 First code segment and result for PickCylinderRayBehavior java Copyright © 2009, IGI Global, distributing in print or electronic forms without written permission of IGI Global is prohibited Ko & Cheng Chapter IX Page 209 Figure 22 Result from PickBoundsBehavior.java Chapter IX Page 212 Figure 25 Signal generator control panel Chapter X Page 234 Figure 16 Second code segment and result for SensorBehavior.java Chapter XI Page 244 Figure Code segment and result for MultiViewApp java Copyright © 2009, IGI Global, distributing in print or electronic forms without written permission of IGI Global is prohibited Appendix I Chapter XI Page 247 Figure Projection policy Chapter XI Page 249 Figure 10 Window eyepoint policy and field of view Chapter XI Page 251 Figure 12 Code segment and result for ViewProjectionApp.java Chapter XI Page 254 Figure 15 Code segment and result for MonoscopicPolicyApp java Chapter XI Page 257 Figure 18 Third code segment and results for ManualEyeApp.java Copyright © 2009, IGI Global, distributing in print or electronic forms without written permission of IGI Global is prohibited Ko & Cheng Chapter XI Page 258 Figure 19 Views from changing eye positions Chapter XI Page 261 Figure 22 Portal view system Chapter XI Page 262 Figure 23 Video wall viewing system Chapter XII Page 270 Figure Code segment and screen capture for MultiViewApp.java Copyright © 2009, IGI Global, distributing in print or electronic forms without written permission of IGI Global is prohibited Appendix I Chapter XII Page 274 Figure Second code segment and result for SoundTest java Chapter XIII Page 277 Figure Virtual room in the real-time oscilloscope experiment Chapter XIII Page 278 Figure Virtual instruments in the real-time oscilloscope experiment Copyright © 2009, IGI Global, distributing in print or electronic forms without written permission of IGI Global is prohibited Ko & Cheng Chapter XIII Page 282 Figure Texture for realizing the front surface of a button test point, a test point, and a clip Chapter XIII Page 285 Figure Navigating Icons Chapter XIII Page 287 Figure Example picking controls on instruments Copyright © 2009, IGI Global, distributing in print or electronic forms without written permission of IGI Global is prohibited About the Authors about the authors Chi Chung Ko received the BSc and PhD degrees in electrical engineering from Loughborough University of Technology, UK He is currently a professor in the department of electrical and computer engineering, National University of Singapore His current research interests include Internet experimentation, digital signal processing, communications and networks He is a senior member of IEEE and has written over 250 technical publications in these areas He has served as an associate editors of the IEEE Transactions on Signal Processing and the IEEE Transactions on Antenna and Propagation He is also an editor for the EURASIP Journal on Wireless Communications and Networking, as well as the ETRI Journal Cheng Chang Dong received the BSEE and MSEE degrees from Harbin Institute of Technology, China, and a PhD degree from Beijing University of Aeronautics and Astronautics, China, in 1990, 1995, and 1999, respectively From 2000 to 2004, he was a research fellow in the department of electrical and computer engineering at the National University of Singapore (NUS) and the Temasek Laboratories at the Nanyang Technological University (NTU) Currently, he is the managing director of NDI Automation PTE LTD (Singapore) Copyright © 2009, IGI Global Copying or distributing in print or electronic forms without written permission of IGI Global is prohibited 0 Index Index Symbols aural environment 269 2D image 129 2D mouse 194 3D computer graphics, interactive 3D graphic, full-immersive 3D graphic, non-immersive 3D graphic, semi-immersive 3D graphics 3D graphics API 11 3D navigation 234 3D sound 3D virtual positions 194 3D virtual world 239 3D visual objects 264 B A activation radius 245 alpha object 133 ambient color 93 ambient light 117, 120 animation 133 animation objects 132 AppearanceCOLOR.java 86 appearance constructor 77 appearance object, relations of 76 appearance objects 75 Artefact() 72 audio 264 background 114 BackgroundSound 265 behavior 133 behavior and animation 133 behavior class 160 Billboard 146 BillboardDemo.java 148, 149, 150, 151, 152 blocking 230 bounding region 163, 164 bounding sphere declaration 164 BranchGroup 27 C camera based viewing model 250 Canvas3D 252 Canvas3D objects 253 changing eye positions, views from 258 Circle1.java 54 clip distance 248 clip policy and distance 248 collision 217 collision detection 235 collision detection behavior 285 collision events 176 Copyright © 2009, IGI Global Copying or distributing in print or electronic forms without written permission of IGI Global is prohibited Index collisions 234 collisions, handling 236 ColoringAttributes 86 ColorInterpolator 146 cone light 122 cone picking shape 201 ConeSound 268 cone sound source 268 constant color background 128 control buttons 282 conventional camera-based view 249 custom behavior 283 cylinder picking shape 206 fog 114, 124 fog, results from using 126 fogdemo.java 124, 125 frame cycle time 252 D H default values 77 demand driven 230 DemoColorInterpolator.java 147 DemoPositionInterpolator.java 136 DemoPositionPathInterpolator.java 137 DemoRotationInterpolator.java 139 DemoRotPosPathInterpolator.java 141 DemoScaleInterpolator.java 142 DemoSphere.java 59, 60 DemoTransparencyInterpolator.java 145 DiamondIndexedTriangleArray.java 62 DiamondIndexedTriangleFanArray.java 70 DiamondIndexedTriangleStripArray.java 68 DiamondTriangleArray.java 43, 44, 45 DiamondTriangleFan.java 55 DiamondTriangleStripArray.java 53 diffuse color 93 directional light 118, 120 DoubleHelix.java 49 head mount display (HMD) 238 Hourglass1.java 51 House_Quad_Array.java 39, 40, 41, 42 E J elapsed time and frame events 176 emissive color 93 events, changes in positions and transforms 180 J3d.java 118, 119 Java 3D 1, 8, 128, 133, 159, 276 Java 3D and applets 110 Java 3D API 18 Java 3D Applet 29 Java 3D application 29 Java3D Application Programming Interface (API) 19 F face normal 116 field of view 248 G geometrical modeling, background 130 GeometryArray Class 35 GeometryArray class hierarchy 35 geometry objects 32 GeometryStripArray 43 geometry subclasses 36 Glass_case() 73 I IndexedGeometryArray 56 IndexedLineArray 56 IndexedLineArray.java 66 IndexedLineStripArray 64 IndexedPointArray 56 IndexedQuadArray 63 IndexedStripArray 63 IndexedTriangleArray 61 IndexedTriangleFanArray 68 IndexedTriangleStripArray 67 input device 229 input devices 217 interaction 159 interactive 3D computer graphics interpolator object 134 Copyright © 2009, IGI Global Copying or distributing in print or electronic forms without written permission of IGI Global is prohibited Index Java 3D overview 18 Java3D program 20 Java3D program for a RotatingCube 20 Java Development Kit (JDK) 19 Java Runtime Environment (JRE) 19 JCreator IDE 19 joystick device driver 229 JoystickInputDevice.java 231, 232 K KeyBoardBehavior 218 KeyBoardBehavior.java 170 keyboard events 168 keyboard navigation 218 KeyBoardNavigation.java 222, 223, 224, 225 KeyBoardUtil.java 220 KeyNavigatorBehavior 219 KeySoundBehavior.java 272 knobs 282 L Laser1.java 55 level of detail (LOD) 153 LightAttenApp.java 123 lighting 114 light scopes 122 LineArray 38 LineArrayStar.java 38 LineAttributes 82 LineAttributesExample1.java 80, 81 LineStripArray 45, 46 LineStripArray object 46 LineStripArraySimpleMaze.java 50 LineTrapez.java 58 LOD.java 153, 154, 155 M main applet 279 ManualEyeApp.java 255, 256, 257 Material_Attribute.java 94 material class 115 material object 93 mixed reality (MR) 10 MonoscopicPolicyApp.java 254 Morph 155 Morph behavior and result 157 Morph class 156 MouseBehaviorUserDefine.java 171, 172, 186 mouse events 168 MouseInteractionUtil.java 226 mouse interaction utility class 225 mouse location inputs 193 MouseNavigation.java 227, 228 mouse utility class 223 MultiLevel.java 107 multilevel texturing 106 multiple geometry classes 69 multiple views 238, 242 multiple view scene graph 243 multitexture 106 Multitexture.java 108, 109 multitexturing 108 MultiViewApp.java 244, 270 Museum_exhibit.java 71 Myearth.java 104 Myearth_applet.java 111, 112 N navigating icons 285 navigation 217 navigation behavior 284 navigation using mouse utility class 223 NodeComponent objects 77 nonblocking 230 normal, baising 117 O OpenGL in 3D graphics programming OpenGL rendering pipeline Oscilloscope.java 213, 214 oscilloscope experiment 276 P PhysicalBody 258 PhysicalBody object and methods 259 PhysicalEnvironment 258 PhysicalEnvironment object and methods 260 PickBehaviour.java 190, 191, 192 PickBoundsBehavior.java 209, 210, 211 Copyright © 2009, IGI Global Copying or distributing in print or electronic forms without written permission of IGI Global is prohibited Index PickCanvas 190, 193 PickConeRayBehavior.java 201, 202, 20 3, 204, 205, 206 PickCylinderRay 207 PickCylinderRayBehavior.java 207, 208 picking 188 picking behavior 188, 286 picking behavior class 193 picking behavior constructor 193 picking classes 189 picking controls on instruments 287 picking in a virtual instrument panel 212 picking objects 209 PickRay 195 PickRayBehaviour.java 196 PickResult 191 PickRotateBehavior 189 PickSegmentBehavior.java 197, 198, 199, 200 PickTool 190, 194 PickTranslateBehavior 189 PickZoomBehavior 189 platform entry and exit events 183 Point.java 57 point and ray picking shape 195 PointArray 37 PointArrayCurve.java 37 PointAttributes 79 PointAttributesExample1.java 79 PointAttributesExample2.java 80 point light 120, 121 PointSound 266 PointSoundScape.java 271 PolygonAttributes 52, 82 PolygonAttributesExample1.java 83, 84 PolygonAttributesExample2.java 85 portal view system 261 PositionInterpolator 135 PositionPathInterpolator 136 post-collision processing 286 PostBehavior.java 173, 174, 175 posted events 169 projection policy 246, 247 Pyramid.java 69 Q Quad.java 64 QuadArray 39 R ray segment picking shape 196 real-time interaction real-time oscilloscope experiment 277, 278 render.java 89 RenderingAttributes 89 right hand coordinate system 36 Rotating color cube 22 RotatingCube, content branch 26 RotatingCube, first part 20 RotatingCube, scene graph 24 RotatingCube, second part 21 RotatingCube, view branch 25 RotatingCube example, scene graph diagram 24 Rotating Cube Program 295 RotationInterpolator 138 RotationPathInterpolator 138 RotPathInter.java 140 RotPosPathInterpolator 140 RotPosScalePathInter.java 143, 144 RotPosScalePathInterpolator 143 S ScaleInterpolator 142 scene graph 279 scene graph basics 22 scene graph implementation 322 screen scale 252 SensorBehavior.java 233, 234 sensor entry and exit events 185 Shape3D 32 Shape3D node 34 Shape3D object, components 33 Shape3D objects 33 Shape3D objects, geometry 33 Shape3D objects, vertices 36 shapes of 3D objects 75 shininess 93 signal generator control panel 212 Copyright © 2009, IGI Global Copying or distributing in print or electronic forms without written permission of IGI Global is prohibited Index SimpleElapsedFrames.java 179 SimpleMouseBehavior.java 161, 162 simple tree structure 23 simple universe 241 SimpleUniverse class 29 Simple Universe scene graph 240 single view 240 sliders 282 software, downloading 290 SoundBackgroundPanel.java 265 SoundConePanel.java 268 SoundPointPanel.java 267 SoundTest.java 273, 274 Speaker1.java 54 specular color 93 Sphere_exhibit.java 87 SphereMap.java 105 spot light 122 SwitchValueInterpolator 144 system reference model 279 T TertahedralMesh.java 65 Tetrahedral1.java 48 TexCoordGenApp.java 105 texture attributes 101 texture coordinate generation 103 texture coordinates 99 texture in applets 110 texture loading 98 texture map transform 103 texture modes 103 texture properties 100 textures 97 TransformChange.java 181, 182 TransformGroup 28 TransparencyAttributes 87 TransparencyInterpolator 145 Trapezium.java 67 Trapezium1.java 47 Trapezium3D.java 47 Triangle.java 61 TriangleArray 42 TriangleFanArray 45, 46, 52 TriangleStripArray 45, 46, 48 U user-defined mouse navigation 227 user defined keyboard navigation 219 Util.java 74 utility class 71 V vertex normal 116 video wall viewing system 262 view attach policy 245 view branch graph 218 ViewManager 301 view model 239 ViewPlatform 164 view platform transform 218 ViewProjectionApp.java 251 virtual 3D oscilloscope 277 virtual 3D world 4, 128, 277 virtual environment (VE) virtual instruments 278 virtual reality 1, virtual reality modeling language (VRML) visibility 252 VRML VRML 1.0 VRML 2.0 VRML97 W WakeupCondition 165 Wakeup condition and criterion 165 Wakeup criteria, combining 185 WakeupCriterion 166 WakeupOnActivationAndDeactivation java 167 WakeupOnAWTEvent 169 WakeupOnBehaviorPost event and usage 173 WakeupOnCollisonEntry event and usage 177 WakeupOnCollisonExit event and usage 177 WakeupOnCollisonMovement event and usage 178 Copyright © 2009, IGI Global Copying or distributing in print or electronic forms without written permission of IGI Global is prohibited Index WakeupOnElapsedFrames 178 WakeupOnElapsedTimeClock.java 180 WakeupOnElapsedTime events and usage 178 WakeupOnPostBehavo event and usage 181 WakeupOnSensorEntry 185 WakeupOnSensorExit 185 WakeupOnViewPlatformEntry 183 WakeupOnViewPlatformExit 183 Web-based 3D experiment, collision detection 355 Web-based 3D experiment, knob class 350 Web-based 3D experiment, main applet for 308 Web-based 3D experiment, navigation 355 Web-based 3D experiment, picking 371 Web-based 3D experiment, scene graph implementation 322 Web-based 3D real time oscilloscope experiment 276 Web-based real time experimentation 280 Web-based virtual reality window eyepoint policy 248 window movement 252 working principle 279 X X3D Z Zoo.java 184 Copyright © 2009, IGI Global Copying or distributing in print or electronic forms without written permission of IGI Global is prohibited ... electronic forms without written permission of IGI Global is prohibited Virtual Reality and Java 3D Figure From real reality to virtual reality Real Reality Mixed/Augmented Reality Virtual Reality. .. us with research funds that lead to this book January 2008 Ko Chi Chung Cheng Chang Dong Singapore Virtual Reality and Java 3D Chapter I Virtual Reality and Java 3D IntroductIon Web- based virtual. .. Virtual Reality and Java 3D Introduction Interactive 3D Computer Graphics Virtual Reality Web- Based Virtual Reality VRML Java 3D