Twist Strip visual object
/*
* 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
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