1 / 101

Java 3D Introduction

Java 3D Introduction. http://www.hta-bi.bfh.ch/~rfs/pwf/java3/ Stefan Rufer Assistant Computer Science Departement rfs@hta-bi.bfh.ch. Todays Contents. Start Introduction to Computer Graphics Java 3D Tutorial Chapters – Layout: Technical Introduction Application in Java 3D

floyd
Download Presentation

Java 3D Introduction

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Java 3D Introduction http://www.hta-bi.bfh.ch/~rfs/pwf/java3/ Stefan Rufer Assistant Computer Science Departement rfs@hta-bi.bfh.ch

  2. Todays Contents • Start • Introduction to Computer Graphics • Java 3D Tutorial Chapters – Layout: • Technical Introduction • Application in Java 3D • Example Programs Java 3D – an Introduction

  3. Start • Foreword • Installing Java 3D • Running Java 3D Programs • Warm-up • Course overview • References & Sources Java 3D – an Introduction

  4. StartObjectives • Appetizer for the Course. • Know how to compile and run Java 3D programs. • Know where to search in case of troubles or further interest. Java 3D – an Introduction

  5. StartForeword • Determine the correct color for every pixel. • This course is programming oriented. • Why to learn Java 3D? • It is object oriented. • It is 3D. • It is fun. Java 3D – an Introduction

  6. StartInstalling Java 3D • School PCs have Java 3D installed • Make sure that JDK 1.2.2 or later has been initialized (NAL -> Java -> Initialize ...). • The SUN environment does not include Java 3D per default • Check web-page for details and troubleshooting # Add some directories to your PATH#original: PATH ${HOME}/bin:${PATH}:PATH /tools/java/JDK-1.2-AND-Java3D-1.1/bin:${HOME}/bin:${PATH}: Java 3D – an Introduction

  7. StartRunning Java 3D Programs • Copy source from intranet • It is so simple – but IF... have a look on the web page for troubleshooting (all JARs at the right place, also in the JRE?). >javac Program.java>java Program Java 3D – an Introduction

  8. StartWarm-up • Simply let us try some examples...! http://www.hta-bi.bfh.ch/~rfs/pwf/java3/Chapter Start, paragraph Warm-up. Java 3D – an Introduction

  9. StartCourse Overview Java 3D – an Introduction

  10. StartReferences & Sources • SUN and intranet web pages, links found in documentation. • Use the glossary, it makes live easier if you know about what exactly you are talking. Java 3D – an Introduction

  11. Intro to Computer Graphics • Why Java 3D • 2D versus 3D • Color Models • Hardware • Java 3D Tutorial Java 3D – an Introduction

  12. Introduction to Computer GraphicsObjectives • Understand some essential basics of computer graphics like color models. • Get an idea of what hardware is involved if doing computer graphics. Java 3D – an Introduction

  13. Introduction to Computer GraphicsWhy Java 3D • 3D-modelers like Art*lantis • Easy content creation • Pre-programmed „static“ behaviour • Many pre-defined shapes, extrusions, textures... • 3D-languages like Java 3D or OpenGL • High degree of user interaction • Start on the „green field“ • Create new 3D applications (CAD, Simulator, ...) • 3D-renderers like PovRay • No interaction, only one picture Java 3D – an Introduction

  14. Introduction to Computer Graphics2D versus 3D • 2D • R2 => R2 • Simply two dimensional • picture on 2D-Screen. • 3D • R3 => R2 • Match three dimensional mathematical model to two dimensional Screen. • A new approach are Holography techniques R3 => R3 but that‘s maybe beyond the scope of this course... Java 3D – an Introduction

  15. Introduction to Computer GraphicsColor Models • RGB is the most most important color model for computer graphics. • Additive system • Red, Green, Blue, 8bit each • Java 3D: each color has values 0..1 • Application example: ColorSpace • Other systems: CMYK, HSB... Java 3D – an Introduction

  16. Introduction to Computer GraphicsHardware (1) • Graphic Cards minimize processor load by executing graphic commands in hardware. • DirectX • OpenGL • Raster Screen have an x-y pixel array (=raster) to display our graphics • CRT • LCD • Counterpart: Vector graphic devices such as analog cathode-ray oscilloscopes. Java 3D – an Introduction

  17. Introduction to Computer GraphicsHardware (2) Java 3D – an Introduction

  18. Introduction to Computer GraphicsJava 3D Tutorial • Tutorial by SUN • Great (as usual, it is SUN...) • Use this and the API as your reference! Java 3D – an Introduction

  19. The Virtual Universe • Basics • Scene Graph • Locales • Content Branch • View Branch • Understanding MyUniverse • Recipe for a simple Program Java 3D – an Introduction

  20. The Virtual UniverseObjectives • Know what a virtual universe and a scene graph is. • Understand the basic parts and elements of a scene graph. • Know the basic recipe for a Java 3D program. Java 3D – an Introduction

  21. The Virtual UniverseBasics • A virtual universe can be seen as a 1:1 representation of our own universe. • Represent structures from astronomical to subatomic. • Floating point 3D space: 2^256 (!!) for each x,y,z. • Decimal point for 1 meter at 2^128 -> incredible precision at incredible extend. • There is one VU-instance only (Singleton). Java 3D – an Introduction

  22. VirtualUniverse The Virtual UniverseScene Graph (1) Locale • Scene Graph is the graphical representation of the objects in our VU. • Directed Acyclic Graph (Tree) • Nodes, arcs, parents, childs, leaves, references and other objects. Group Link Leaf Reference NodeComponent Other objects Java 3D – an Introduction

  23. The Virtual UniverseScene Graph (2) • A Java 3D program may have more objects than those in the scene graph. • A scene graph drawing is the correct documentation for the 3D part of a Java 3D program. Java 3D – an Introduction

  24. The Virtual UniverseScene Graph (3) myVirtualUniverse • Basic parts of a scene graph myLocale Locale(s) BranchGroup BranchGroup Content Branch View Branch a3Dobject myViewPlatform Java 3D – an Introduction

  25. The Virtual UniverseLocales (1) • How to handle the huge extend of a virtual universe efficiently? • Our virtual universe contains at least one Locale. • The locale is a 3D-reference point inside the virtual universe. Java 3D – an Introduction

  26. The Virtual UniverseLocales (2) • Standard Locale resides at (0,0,0) in the VU. • We can have several Locales, eg: • One as reference point of the swiss coordinate system (located in Bordeaux, France). • A second as the architects reference point of a building plan. • The both are related, but depending on the point of view it is more convenient (and precise) to work with one or the other. Java 3D – an Introduction

  27. The Virtual UniverseContent Branch (1) • Contains all „visible“ objects of our scene. • Contains all transformations for those objects (displacement, animation, ...). • We distinguish between group nodes and leaf nodes (see following slide). Java 3D – an Introduction

  28. The Virtual UniverseContent Branch (2) • The most common object types Branch Group ... Transform Group ... Appearance Shape3D Java 3D – an Introduction

  29. The Virtual UniverseView Branch The Canvas3D will be inserted in our application or applet -> most important! Java 3D – an Introduction

  30. The Virtual UniverseRecipe for a simple Program • Create a Frame & a Canvas3D object. • Create a SimpleUniverse object which gets a reference to the Canvas3D. • Construct the content branch. • Insert the content branch into the Locale of the SimpleUniverse. Java 3D – an Introduction

  31. The Virtual UniverseExercises • Check Web-Page, chapter „Virtual Universe“ http://www.hta-bi.bfh.ch/~rfs/pwf/java3/ Java 3D – an Introduction

  32. Hello World • The Java 3D API • Finally: Hello World! • Source Code • Class Diagram of HelloJava3D • What happens when running? • Exercises Java 3D – an Introduction

  33. Hello WorldObjectives • Understand the high-level structure of the APIs involved in a Java 3D program. • Understand the code of the HelloJava3Da example line by line. Java 3D – an Introduction

  34. Hello WorldThe Java 3D API • Packages related to the Java 3D API: • Core classes: javax.media.j3d • Utility classes: com.sun.j3d.utils • Math classes: javax.vecmath • AWT classes: javax.swing Java 3D – an Introduction

  35. Hello WorldFinally: Hello World! • Probably the most simple Scene Graph  Java 3D – an Introduction

  36. Hello WorldSource Code public class HelloJava3Da extends Applet { public HelloJava3Da() { setLayout(new BorderLayout()); Canvas3D canvas3D = new Canvas3D(null); add("Center", canvas3D); SimpleUniverse simpleU = new SimpleUniverse(canvas3D); simpleU.getViewingPlatform().setNominalViewingTransform(); BranchGroup scene = createSceneGraph(); simpleU.addBranchGraph(scene); } public BranchGroup createSceneGraph() { BranchGroup objRoot = new BranchGroup(); objRoot.addChild(new ColorCube(0.4)); return objRoot; } public static void main(String[] args) { Frame frame = new MainFrame(new HelloJava3Da(), 256, 256); } } Java 3D – an Introduction

  37. Hello WorldClass Diagram of HelloJava3D Java 3D – an Introduction

  38. Hello WorldWhat happens when running? while (true) { Process input Perform Behaviours //none at the moment Traverse scene graph and render visual objects if (request to exit) break } Cleanup and exit Java 3D – an Introduction

  39. Hello WorldExercises • Check Web-Page, chapter „Hello World“ http://www.hta-bi.bfh.ch/~rfs/pwf/java3/ Java 3D – an Introduction

  40. Creating Content • Geometic Utility Classes • Mathematical Classes • Geometry Classes • GeometryArray Classes • GeometryStrip Array Classes • Indexed Geometry • Appearance and Attributes • Point- + LineAttributes • PolygonAttributes Java 3D – an Introduction

  41. Creating ContentObjectives • Get an overview on how to handle polygones in Java 3D. • Know the most important attributes that determine the look of a polygone. Java 3D – an Introduction

  42. Tutorial Page 2-6 Creating ContentGeometric Utility Classes • Box (2x2x2 m) • Cone (Ø2m, height 2m) • Cylinder (Ø2m, height 2m) • Sphere (Ø2m) • Default color white Java 3D – an Introduction

  43. Tutorial Page 2-15 Creating ContentMathematical Classes (1) • Tuples are simply pairs or triples of numbers. • For each vertex there can be up to four javax.vecmath objects: • Points for coordinates • Colors • Vectors for normals • TexCoords for texture coordinates Java 3D – an Introduction

  44. Creating ContentMathematical Classes (2) • Vectors: mostly used for normals and position information in 3D-space. • Normals: determined using the right hand (remember: we have a right-handed system). P2 n P0 P1 Java 3D – an Introduction

  45. Tutorial Page 2-20 Creating ContentGeometry Classes • What to do if our shape is not a box or a cylinder? • Create Shape3D-object, use setGeometry() method! • For a triangle: • Three-element array • One point per element Java 3D – an Introduction

  46. Tutorial Page 2-212-26 Creating ContentGeometryArray Classes • Most primitive form to create shapes: • Points or lines are one pixel wide per default. • Colors are interpolated from vertex to vertex if specified.(see code page 2-24, line 9+10) P0 P1 Java 3D – an Introduction

  47. Tutorial Page 2-27 Creating ContentGeometryStripArray Classes • More convenient: share some vertices: • Example Yoyo: Ever tried to model a Jumbo-Jet by hand? Often geometry is generated by mathematical calculations. Java 3D – an Introduction

  48. Tutorial Page 2-27 Creating ContentIndexed Geometry • Best re-use of vertices but we lose performance using the index array. Java 3D – an Introduction

  49. Tutorial Page 2-34 Creating ContentAppearance and Attributes • Appearance class does not specify the appearance directrly but contains many links to appearance objects: Java 3D – an Introduction

  50. Tutorial Page 2-37 Creating ContentPoint- + LineAttributes • Points and Lines are 1 pixel wide by default. Zooming does not affect this. • Let‘s try to change: • Thikness of the line • Antialiasing Java 3D – an Introduction

More Related