java 3d 的问题?

代码如下:
import com.sun.j3d.utils.applet.MainFrame;
import com.sun.j3d.utils.geometry.Cone;
import com.sun.j3d.utils.geometry.Primitive;
import com.sun.j3d.utils.universe.*;
import javax.media.j3d.*;
import javax.vecmath.*;
public class MyCone extends Applet{
public BranchGroup createSceneGraph(){
BranchGroup objRoot = new BranchGroup();
TransformGroup objTrans = new TransformGroup();
objRoot.addChild(objTrans);
BoundingSphere bounds = new BoundingSphere(new Point3d(0.0,0.0,0.0),100.0);
Color3f bgColor = new Color3f(0.0f,0.0f,0.0f);
Background bg = new Background(bgColor);
bg.setApplicationBounds(bounds);
objRoot.addChild(bg);
Color3f directionalColor = new Color3f(1.f,1.f,1.f);
Vector3f vec = new Vector3f(0.f,0.f,-1.0f);
DirectionalLight directionalLight = new DirectionalLight(directionalColor,vec);
directionalLight.setInfluencingBounds(bounds);
objRoot.addChild(directionalLight);
Appearance app = new Appearance();
Material material = new Material();
material.setDiffuseColor(new Color3f(1.0f,1.0f,1.0f));
app.setMaterial(material);
Cone cone = new Cone(0.5f,1.0f,1,app);
objRoot.addChild(cone);
return objRoot;
}
public MyCone(){
setLayout(new BorderLayout());
Canvas3D c = new Canvas3D();
add("Center",c);
BranchGroup scene = createSceneGraph();
scene.compile();
SimpleUniverse u = new SimpleUniverse(c);
u.getViewingPlatform().setNominalViewingTransform();
u.addBranchGraph(scene);
}
public static void main(String[] args){
new MainFrame(new MyCone(),400,300);
}
}
编译无问题,运行却出现这样的问题:
exception in thread "main" java.lang.noclassdeffouderror:MyCone(wrong name:MyCone)
at java.lang.classloader.defineclass(native method)
at java.lang.classloader.defineclass(classloader.java:620)
.......