Java tutorial
/* * LitTwistApp.java 1.0 99/02/19 * * Copyright (c) 1999 Sun Microsystems, Inc. All Rights Reserved. * * Sun grants you ("Licensee") a non-exclusive, royalty free, license to use, * modify and redistribute this software in source and binary code form, * provided that i) this copyright notice and license appear on all copies of * the software; and ii) Licensee does not utilize the software in a manner * which is disparaging to Sun. * * This software is provided "AS IS," without a warranty of any kind. ALL * EXPRESS OR IMPLIED CONDITIONS, REPRESENTATIONS AND WARRANTIES, INCLUDING ANY * IMPLIED WARRANTY OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE OR * NON-INFRINGEMENT, ARE HEREBY EXCLUDED. SUN AND ITS LICENSORS SHALL NOT BE * LIABLE FOR ANY DAMAGES SUFFERED BY LICENSEE AS A RESULT OF USING, MODIFYING * OR DISTRIBUTING THE SOFTWARE OR ITS DERIVATIVES. IN NO EVENT WILL SUN OR ITS * LICENSORS BE LIABLE FOR ANY LOST REVENUE, PROFIT OR DATA, OR FOR DIRECT, * INDIRECT, SPECIAL, CONSEQUENTIAL, INCIDENTAL OR PUNITIVE DAMAGES, HOWEVER * CAUSED AND REGARDLESS OF THE THEORY OF LIABILITY, ARISING OUT OF THE USE OF * OR INABILITY TO USE SOFTWARE, EVEN IF SUN HAS BEEN ADVISED OF THE POSSIBILITY * OF SUCH DAMAGES. * * This software is not designed or intended for use in on-line control of * aircraft, air traffic, aircraft navigation or aircraft communications; or in * the design, construction, operation or maintenance of any nuclear facility. * Licensee represents and warrants that it will not use or redistribute the * Software for such purposes. */ /* * LitTwistApp.java is intended to demonstrate lighting complex surfaces A Twist * strip is a continuous surface with a complete twist in it. (As opposed to a * half-twist which would make a Mobius Strip.) The Class Twist creates a * surface using a TriangleStripArray. A Twist strip is placed in a scene graph * with a RotationInterpolator so the strip spins. * * One Twist strip is created using the inner class (Twist). This visual object * is rendered as filled polygons. * * This application (or a version of it) generated one or more of the images in * Chapter 6 of Getting Started with the Java 3D API. The Java 3D Turtorial. * * See http://www.sun.com/desktop/java3d/collateral for more information. * */ import java.applet.Applet; import java.awt.BorderLayout; import java.awt.Frame; import javax.media.j3d.Alpha; import javax.media.j3d.Appearance; import javax.media.j3d.Background; import javax.media.j3d.BoundingSphere; import javax.media.j3d.BranchGroup; import javax.media.j3d.Canvas3D; import javax.media.j3d.DirectionalLight; import javax.media.j3d.Geometry; import javax.media.j3d.Material; import javax.media.j3d.PolygonAttributes; import javax.media.j3d.RotationInterpolator; import javax.media.j3d.Shape3D; import javax.media.j3d.TransformGroup; import javax.media.j3d.TriangleStripArray; import javax.vecmath.Color3f; import javax.vecmath.Point3d; import javax.vecmath.Vector3f; import com.sun.j3d.utils.applet.MainFrame; import com.sun.j3d.utils.universe.SimpleUniverse; public class LitTwistApp extends Applet { ///////////////////////////////////////////////// // // create Twist Strip visual object // public class Twist extends Shape3D { //////////////////////////////////////////// // // create twisted strip subgraph // public Twist() { this.setGeometry(createGeometry()); this.setAppearance(createAppearance()); } // end of Twist constructor Geometry createGeometry() { TriangleStripArray twistStrip; Color3f blue = new Color3f(0.0f, 0.0f, 1.0f); // create triangle strip for Twist int N = 80; int stripCounts[] = { N }; twistStrip = new TriangleStripArray(N, TriangleStripArray.COORDINATES | TriangleStripArray.NORMALS, stripCounts); double a; int v; Vector3f norm = new Vector3f(); for (v = 0, a = 0.0; v < N; v += 2, a = v * 2.0 * Math.PI / (N - 2)) { twistStrip.setCoordinate(v, new Point3d(0.7 * Math.cos(a) + 0.2 * Math.sin(a), -0.3 * Math.cos(a), 0.7 * Math.sin(a) + 0.2 * Math.sin(a))); twistStrip.setCoordinate(v + 1, new Point3d(0.7 * Math.cos(a) - 0.2 * Math.sin(a), 0.3 * Math.cos(a), 0.7 * Math.sin(a) - 0.2 * Math.sin(a))); norm.set((float) (Math.abs(Math.cos(a))), (float) Math.abs(Math.sin(a)), (float) (Math.cos(a) * Math.sin(a))); norm.normalize(); twistStrip.setNormal(v, norm); twistStrip.setNormal(v + 1, norm); } return twistStrip; } // create Appearance for Twist Strip // // this method creates the default Appearance for the // twist strip. The commented line of code containting // the setCullFace will fix the problem of half of the // Twist Strip disappearing. Appearance createAppearance() { Appearance twistAppear = new Appearance(); PolygonAttributes polyAttrib = new PolygonAttributes(); polyAttrib.setCullFace(PolygonAttributes.CULL_NONE); polyAttrib.setBackFaceNormalFlip(true); twistAppear.setPolygonAttributes(polyAttrib); Material material = new Material(); twistAppear.setMaterial(material); return twistAppear; } } // end of class Twist ///////////////////////////////////////////////// // // create scene graph branch group // public BranchGroup createSceneGraph() { BranchGroup contentRoot = new BranchGroup(); // Create the transform group node and initialize it to the // identity. Add it to the root of the subgraph. TransformGroup objSpin = new TransformGroup(); objSpin.setCapability(TransformGroup.ALLOW_TRANSFORM_WRITE); contentRoot.addChild(objSpin); Shape3D twist = new Twist(); objSpin.addChild(twist); Alpha rotationAlpha = new Alpha(-1, 16000); RotationInterpolator rotator = new RotationInterpolator(rotationAlpha, objSpin); // a bounding sphere specifies a region a behavior is active // create a sphere centered at the origin with radius of 1.5 BoundingSphere bounds = new BoundingSphere(); bounds.setRadius(1.5); rotator.setSchedulingBounds(bounds); objSpin.addChild(rotator); DirectionalLight lightD = new DirectionalLight(); lightD.setInfluencingBounds(bounds); contentRoot.addChild(lightD); Background background = new Background(); background.setColor(1.0f, 1.0f, 1.0f); background.setApplicationBounds(bounds); contentRoot.addChild(background); // Let Java 3D perform optimizations on this scene graph. // contentRoot.compile(); return contentRoot; } // end of CreateSceneGraph method of LitTwistApp // Create a simple scene and attach it to the virtual universe public LitTwistApp() { setLayout(new BorderLayout()); Canvas3D canvas3D = new Canvas3D(null); add("Center", canvas3D); BranchGroup scene = createSceneGraph(); // SimpleUniverse is a Convenience Utility class SimpleUniverse simpleU = new SimpleUniverse(canvas3D); // This will move the ViewPlatform back a bit so the // objects in the scene can be viewed. simpleU.getViewingPlatform().setNominalViewingTransform(); simpleU.addBranchGraph(scene); } // end of LitTwistApp constructor // The following allows this to be run as an application // as well as an applet public static void main(String[] args) { System.out.println("LitTwistApp - Java 3D"); System.out.println("A demonstration of lights."); Frame frame = new MainFrame(new LitTwistApp(), 256, 256); } // end of main method of TwistApp } // end of class LitTwistApp