FileDocCategorySizeDatePackage
TwistStripApp.javaAPI DocExample8717Fri Sep 22 17:13:14 BST 2000None

TwistStripApp

public class TwistStripApp extends Applet

Fields Summary
Constructors Summary
public TwistStripApp()

        setLayout(new BorderLayout());
        GraphicsConfiguration config =
           SimpleUniverse.getPreferredConfiguration();

        Canvas3D canvas3D = new Canvas3D(config);
        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);
Methods Summary
public BranchGroupcreateSceneGraph()


        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);

        // Duplicate the twist strip geometry and set the
        // appearance of the new Shape3D object to line mode
        // without culling.
        // Add the POLYGON_FILLED and POLYGON_LINE strips
        // in the scene graph at the same point.
        // This will show the triangles of the original Mobius strip that
        // are clipped.  The PolygonOffset is set to prevent stitching.
        PolygonAttributes polyAttrib = new PolygonAttributes();
        polyAttrib.setCullFace(PolygonAttributes.CULL_NONE);
        polyAttrib.setPolygonMode(PolygonAttributes.POLYGON_LINE);
        polyAttrib.setPolygonOffset(0.001f);
        Appearance polyAppear = new Appearance();
        polyAppear.setPolygonAttributes(polyAttrib);
        objSpin.addChild(new Shape3D(twist.getGeometry(), polyAppear));

        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
        BoundingSphere bounds = new BoundingSphere();
        rotator.setSchedulingBounds(bounds);
        objSpin.addChild(rotator);

        // make background white
        Background background = new Background(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;
public static voidmain(java.lang.String[] args)

        System.out.println("TwistStripApp - Java 3D API");
        System.out.println("This program demonstrates back face culling.");
        System.out.print("In this program two visual objects rotate, ");
        System.out.println("one wireframe and one solid surface.");
        System.out.print("The wire frame is visible only when components");
        System.out.println(" of the surface are culled.");

        Frame frame = new MainFrame(new TwistStripApp(), 256, 256);