public void addLight(SimpleUniverse su)
{
BranchGroup bgLight = new BranchGroup();
BoundingSphere bounds = new BoundingSphere(new Point3d(0.0,0.0,0.0), Double.MAX_VALUE);
Color3f lightColour1 = new Color3f(1.0f,1.0f,1.0f);
Vector3f lightDir1 = new Vector3f(0.2f,-0.1f,-1.0f);
DirectionalLight light1 = new DirectionalLight(lightColour1, lightDir1);
light1.setInfluencingBounds(bounds);