Creating Games with the Open-Source Multithreaded Game Engine (MT Game) Doug Twilleager Deron Johnson Sun Microsystems

Transcription

1 Creating Games with the Open-Source Multithreaded Game Engine (MT Game) Doug Twilleager Deron Johnson Sun Microsystems

2 Agenda > Background > Features > Architecture > Feature Details > Working Game > Looking Forward 2

3 Background > Wonderland needed a new rendering engine WL is a collaborative virtual world technology > Java Monkey Engine (jme) was chosen Collection of rendering utilities Lacked a processing model Lacked an object model > Led to the creation of the Multithreaded Game Engine (MT Game) > Demo 3

4 Agenda > Background > Features > Architecture > Feature Details > Working Game > Looking Forward 4

5 Features > Component Based > Uniform Render Buffer System > Collada Model Import > Virtual Processing System > Input Processing > Collision System > Physics System > Shaders 5

6 Agenda > Background > Features > Architecture > Feature Details > Working Game > Looking Forward 6

7 Architecture Component Based Architecture Hierarchical Architecture Entity Entities Avatar Component Architecture Input Physics Collision Object Character NPC AI Physics Collision Moveable Avatar NPC Moveable Physics Collision 7

8 Architecture Component Based Architecture > Functionality Encompassed in a Component > Components are Created By Managers RenderComponent => RenderManager > Managers Optimize Allocation/Processing > New Components Can Be Added On Demand > Slightly More Overhead But much more flexible and maintainable 8

9 Agenda > Background > Features > Architecture > Feature Details > Working Game > Looking Forward 9

10 Uniform Render Buffer System > Onscreen and offscreen buffers treated the same > Can have multiple buffers in one rendered frame > Allows for many advanced rendering techniques Mirrors Shadows Portals 10

11 Getting The System Bootstrapped > WorldManager Manages All Managers > Creating RenderBuffers worldmanager = new WorldManager("DefaultWorld"); rendermanager = worldmanager.getrendermanager(); renderbuffer = rendermanager.createrenderbuffer(renderbuffer.target.onscreen, width, height); rendermanager.addrenderbuffer(renderbuffer); canvas = renderbuffer.getcanvas(); offscreenbuffer = rendermanager.createrenderbuffer(renderbuffer.target.texture_2d, width, height); rb.setcameracomponent(cameracomponent); rendermanager.addrenderbuffer(offscreenbuffer); 11

12 RenderComponent > Represents a jme Scene Graph to Render > Creating a RenderComponent Node node = new Node(); Teapot teapot = new Teapot(); teapot.updategeometrydata(); node.attachchild(teapot); rendercomponent = rendermanager.createrendercomponent(teapot); Entity entity = new Entity("Teapot "); entity.addcomponent(rendercomponent.class, rendercomponent); worldmanager.addentity(entity); 12

13 Collada Model Support > Support For Import of Collada Models Maya, 3DS Max, Softimage XSI Google 3D Warehouse > Collada Model Features Currently Supported Geometry Textures and Texture Coordinates CGFX Shaders (TBD) 13

14 Collada Model Support > Loading a Collada Model try { filestream = new FileInputStream(filename); } catch (FileNotFoundException ex) { System.out.println(ex); } ColladaImporter.load(fileStream, "Model"); Node model = ColladaImporter.getModel(); rendercomponent = rendermanager.createrendercomponent(teapot); Entity entity = new Entity("Collada Model "); entity.addcomponent(rendercomponent.class, rendercomponent); worldmanager.addentity(entity); 14

15 Virtual Processing System > Virtual Processors > Disconnected From The Renderer Processors run at independent rates > Level of Detail Techniques on Processors Ranging from frame synced to completely off > Highly Scalable Presenting a single thread of execution to developer 15

16 Virtual Processing System > Processors Are Triggered By Conditions New Frame Timer Post Event AWT Event Armed > Processors Are Two-Phased Compute Commit Rearmed Commit Triggered Compute 16

17 ProcessorComponent > Initialization Set up the condition > Compute Any processing needed by the object Not render bound > Commit Update any jme objects Limit time spent here it happens in the render loop 17

18 ProcessorComponent Example > RotationProcessor public void initialize() { setarmingcondition(new NewFrameCondition(this)); } public void compute(processorarmingcollection collection) { degrees += increment; quaternion.fromangles(0.0f, degrees, 0.0f); } public void commit(processorarmingcollection collection) { target.setlocalrotation(quaternion); worldmanager.addtoupdatelist(target); } 18

19 ProcessorComponent Example > Adding To Entity RotationProcessor rp = new RotationProcessor("Teapot Rotator", worldmanager, teapot, (float) (6.0f * Math.PI / 180.0f)); entity.addcomponent(rotationprocessor.class, rp); worldmanager.addentity(entity); // Support a collection of processors in one entity ProcessorCollectionComponent pcc = new ProcessorCollectionComponent(); RotationProcessor rp = new RotationProcessor("Teapot Rotator", worldmanager, teapot, (float) (6.0f * Math.PI / 180.0f)); pcc.addprocessor(rp); entity.addcomponent(processorcollectioncomponent.class, pcc); worldmanager.addentity(e); 19

20 Input System > Currently Support AWT Events > Separate Catching Events From Processing AWTInputComponent used to catch events AWTEventProcessorComponent used for processing > Needed to Keep Catching Events While Processing 20

21 Input System > AWT Event Processor Example int eventmask = InputManager.KEY_EVENTS InputManager.MOUSE_EVENTS; InputManager im = worldmanager.getinputmanager(); AWTInputComponent eventlistener = (AWTInputComponent)im.createInputComponent(canvas, eventmask); OrbitCameraProcessor eventprocessor = new OrbitCameraProcessor(eventListener, cameranode, worldmanager, camera); public void compute(processorarmingcollection collection) { Object[] events = getevents();. } 21

22 Collision System > Multiple Simultaneous Collision Systems Supported CollisionManager loads a specified system > CollisionComponents are Created From Appropriate System CollisionSystem does NOT automatically utilize RenderComponent's > CollisionSystems Can Optimize Their Structures and Processing 22

23 Collision System > Currently Support jme and jbullet Collision JMECC JMECC JMECollisionSystem JMECC JMECC CollisionManager JBulletCC JBulletCC JBulletCollisionSystem JBulletCC JBulletCC 23

24 Collision System > jme Collision Example // Initialize the jme Collision System CollisionManager cm = worldmanager.getcollisionmanager(); JMECollisionSystem collisionsystem = (JMECollisionSystem)cm.loadCollisionSystem(JMECollisionSystem.class); // Create and add a jme CollisionComponent JMECollisionComponent cc = collisionsystem.createcollisioncomponent(model); entity.addcomponent(jmecollisioncomponent.class, cc); // Example of a picking query TrianglePickResults trianglepickresults = new TrianglePickResults(); Ray ray = new Ray(); ray.setorigin(origin); ray.setdirection(direction); collisionsystem.pickall(ray, trianglepickresults, false, cameracomponent); 24

25 Physics System > Physics is Layered On Top of Collision > The Physics System Takes Over an Object's Behavior > All Objects That Interact Must Have Physics/Collision Representation > Currently Only Support jbullet Physics One of the most popular systems today 25

26 Physics System > jbullet Physics Example // Initialize the jbullet Physics System PhysicsManager pm = worldmanager.getphysicsmanager(); JBulletPhysicsSystem physicssystem = (JBulletPhysicsSystem) pm.loadphysicssystem(jbulletphysicssystem.class, collisionsystem); // Create a ground plane to collide with CollisionShape groundshape = new StaticPlaneShape(new javax.vecmath.vector3f(0, 1, 0), 0); cc = collisionsystem.createcollisioncomponent(groundshape); pc = physicssystem.createphysicscomponent(cc); // Create and add the objects cc = collisionsystem.createcollisioncomponent(teapot); pc = physicssystem.createphysicscomponent(cc); pc.setmass(.01f); 26

27 Advanced Rendering Techniques: Shaders > Shaders Allow Applications to Write Custom Graphics Code > Support For Shaders in Many Systems jme, JOGL, Java 3D > Single Shader for Each Object > MT Game Extends This to Support Level of Detail (LOD) Shaders 27

28 Advanced Rendering Techniques: Shaders > High, Medium, and Low LOD Shaders Low Shader Medium Shader High Shader Viewer 28

29 Agenda > Background > Features > Architecture > Feature Details > Working Game > Looking Forward 29

30 Working Game Portals Clone > Features Used In This Game Rendering Stencil Buffers Multiple screen renders per frame Collision/Picking Physics LOD Shaders 30

31 Agenda > Background > Features > Architecture > Feature Details > Working Game > Looking Forward 31

32 Looking Forward > Particle Systems > Global Illumination > Terrain > World Deformation and Fracture > Decals > Direct Animation Import From Collada 32

33 More Information: mtgame.dev.java.net > TS-4010 Duke's Dancing Partner: Connecting Handheld Game Consoles with Java Technology > TS-4575 Project Darkstar: A Scalable Application Server for Networked Games, Virtual Worlds, and MMOGs Wednesday 4:10 PM - 5:10 PM > BOF-5131 Project Wonderland: Build 3-D Virtual Worlds with Java Technology Wednesday 6:45 PM - 7:35 PM > LAB-5562 Project Snowman: Developing a 3-D Multiplayer Game, Using Project Darkstar 33

34 Doug Twilleager Deron Johnson