This Java tip builds up a simple scene from primitives. It builds a circular 'house' with a conical 'roof', and then creates three 'trees' made up of cylinders and spheres. All this is place on a ground made up of a cube.

 import java.awt.BorderLayout;
import java.awt.Button;
import java.awt.Frame;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;

import javax.media.j3d.Appearance;
import javax.media.j3d.BoundingSphere;
import javax.media.j3d.BranchGroup;
import javax.media.j3d.Canvas3D;
import javax.media.j3d.DirectionalLight;
import javax.media.j3d.Locale;
import javax.media.j3d.Material;
import javax.media.j3d.Node;
import javax.media.j3d.PhysicalBody;
import javax.media.j3d.PhysicalEnvironment;
import javax.media.j3d.Transform3D;
import javax.media.j3d.TransformGroup;
import javax.media.j3d.View;
import javax.media.j3d.ViewPlatform;
import javax.media.j3d.VirtualUniverse;
import javax.vecmath.AxisAngle4d;
import javax.vecmath.Color3f;
import javax.vecmath.Point3d;
import javax.vecmath.Vector3f;

import com.sun.j3d.utils.geometry.Box;
import com.sun.j3d.utils.geometry.Cone;
import com.sun.j3d.utils.geometry.Cylinder;
import com.sun.j3d.utils.geometry.Primitive;
import com.sun.j3d.utils.geometry.Sphere;

/**
 * This builds up a simple scene from primitives. It builds a circular 'house'
 * with a conical 'roof', and then creates three 'trees' made up of cylinders
 * and spheres. All this is place on a ground made up of a cube.
 * 
 * @author I.J.Palmer
 * @version 1.0 */
public class SimpleCombine extends Frame implements ActionListener {
  protected Canvas3D myCanvas3D = new Canvas3D(null);

  protected Button myButton = new Button("Exit");

  /**
   * This function builds the view branch of the scene graph. It creates a
   * branch group and then creates the necessary view elements to give a
   * useful view of our content.
   * 
   * @param c
   *            Canvas3D that will display the view
   * @return BranchGroup that is the root of the view elements
   */
  protected BranchGroup buildViewBranch(Canvas3D c) {
    BranchGroup viewBranch = new BranchGroup();
    Transform3D viewXfm = new Transform3D();
    viewXfm.set(new Vector3f(0.0f, 0.0f, 7.0f));
    TransformGroup viewXfmGroup = new TransformGroup(viewXfm);
    ViewPlatform myViewPlatform = new ViewPlatform();
    PhysicalBody myBody = new PhysicalBody();
    PhysicalEnvironment myEnvironment = new PhysicalEnvironment();
    viewXfmGroup.addChild(myViewPlatform);
    viewBranch.addChild(viewXfmGroup);
    View myView = new View();
    myView.addCanvas3D(c);
    myView.attachViewPlatform(myViewPlatform);
    myView.setPhysicalBody(myBody);
    myView.setPhysicalEnvironment(myEnvironment);
    return viewBranch;
  }

  /**
   * Add some lights so that we can illuminate the scene. This adds one
   * ambient light to bring up the overall lighting level and one directional
   * shape to show the shape of the objects in the scene.
   * 
   * @param b
   *            BranchGroup that the lights are to be added to.
   */
  protected void addLights(BranchGroup b) {
    BoundingSphere bounds = new BoundingSphere(new Point3d(0.0, 0.0, 0.0),
        100.0);
    Color3f lightColour1 = new Color3f(1.0f, 1.0f, 1.0f);
    Vector3f lightDir1 = new Vector3f(-1.0f, -1.0f, -1.0f);
    Color3f lightColour2 = new Color3f(1.0f, 1.0f, 1.0f);
    Vector3f lightDir2 = new Vector3f(1.0f, -1.0f, -1.0f);
    DirectionalLight light1 = new DirectionalLight(lightColour1, lightDir1);
    light1.setInfluencingBounds(bounds);
    DirectionalLight light2 = new DirectionalLight(lightColour2, lightDir2);
    light2.setInfluencingBounds(bounds);
    b.addChild(light1);
    b.addChild(light2);
  }

  /**
   * This builds the content branch of our scene graph. The root of the shapes
   * supplied as a parameter is slightly tilted to reveal its 3D shape. It
   * also uses the addLights function to add some lights to the scene.
   * 
   * @param shape
   *            Node that represents the geometry for the content
   * @return BranchGroup that is the root of the content branch
   */
  protected BranchGroup buildContentBranch(Node shape) {
    BranchGroup contentBranch = new BranchGroup();
    Transform3D rotateCube = new Transform3D();
    rotateCube.set(new AxisAngle4d(1.0, 1.0, 0.0, Math.PI / 4.0));
    TransformGroup rotationGroup = new TransformGroup(rotateCube);
    contentBranch.addChild(rotationGroup);
    rotationGroup.addChild(shape);
    addLights(contentBranch);
    return contentBranch;
  }

  /**
   * This defines the shapes used in the scene. The function uses the utility
   * geometries sphere, box, cone and cylinder to build a simple scene. This
   * demonstrates the use of transformations to group and position items.
   * 
   * @return Node that is the root of the shape hierarchy.
   */
  protected Node buildShape() {
    //Create a root for the shapes in the scene
    BranchGroup theScene = new BranchGroup();
    //Create an appearance for the ground
    Appearance groundApp = new Appearance();
    Color3f groundColour = new Color3f(0.0f, 0.5f, 0.0f);
    Color3f emissiveColour = new Color3f(0.0f, 0.0f, 0.0f);
    Color3f specularColour = new Color3f(0.5f, 0.5f, 0.5f);
    float shininess = 10.0f;
    groundApp.setMaterial(new Material(groundColour, emissiveColour,
        groundColour, specularColour, shininess));
    //Create a box that will be the ground
    Box ground = new Box(100.0f, 0.1f, 100.0f, groundApp);
    //Create a transform and a transform group that
    //will position the ground
    Transform3D grndXfm = new Transform3D();
    grndXfm.set(new Vector3f(0.0f, -1.0f, 0.0f));TransformGroup grndXfmGrp = 
  new TransformGroup(grndXfm);

    //Add the ground shape to the group
    grndXfmGrp.addChild(ground);
    //Add the ground group to the scene group
    theScene.addChild(grndXfmGrp);
    //Create an appearance for the wall of the house
    Appearance wallApp = new Appearance();
    Color3f wallColour = new Color3f(0.5f, 0.5f, 0.5f);
    wallApp.setMaterial(new Material(wallColour, emissiveColour,
        wallColour, specularColour, shininess));
    //Create a cylinder that is the wall of the house
    Cylinder walls = new Cylinder(1.0f, 1.0f, Primitive.GENERATE_NORMALS,
        wallApp);
    //Create a group that will be the root of the house
    TransformGroup house = new TransformGroup();
    //Add the walls to the house group
    house.addChild(walls);
    //Create an appearance for the roof
    Appearance roofApp = new Appearance();
    Color3f roofColour = new Color3f(0.5f, 0.0f, 0.0f);
    roofApp.setMaterial(new Material(roofColour, emissiveColour,
        roofColour, specularColour, shininess));
    //Create a cone that will be the roof
    Cone myRoof = new Cone(1.0f, 1.0f, Primitive.GENERATE_NORMALS, roofApp);
    //Create the transform and transform group that will position the
    //roof on the house
    Transform3D roofXfm = new Transform3D();
    roofXfm.set(new Vector3f(0.0f, 1.0f, 0.0f));
    TransformGroup roofXfmGrp = new TransformGroup(roofXfm);
    //Add the roof to the roof transform group
    roofXfmGrp.addChild(myRoof);
    //Add the roof group to the house
    house.addChild(roofXfmGrp);
    //Create an appearance for the tree trunks
    Appearance trunkApp = new Appearance();
    Color3f trunkColour = new Color3f(0.2f, 0.2f, 0.0f);
    trunkApp.setMaterial(new Material(trunkColour, emissiveColour,
        trunkColour, specularColour, shininess));
    //Create an appearance for the tree leaves
    Appearance leafApp = new Appearance();
    Color3f leafColour = new Color3f(0.0f, 0.2f, 0.0f);
    leafApp.setMaterial(new Material(leafColour, emissiveColour,
        leafColour, specularColour, shininess));
    //Create a transform and transform group for the tree
    Transform3D treeXfm = new Transform3D();
    treeXfm.set(new Vector3f(-2.0f, 0.0f, 0.5f));
    TransformGroup treeXfmGrp = new TransformGroup(treeXfm);
    //Create a cylinder for the tree trunk
    Cylinder myTrunk = new Cylinder(0.1f, 1.0f, trunkApp);
    //Add the trunk to the tree group
    treeXfmGrp.addChild(myTrunk);
    //Create a transform and transform group for the tree leaves
    Transform3D leafXfm = new Transform3D();
    leafXfm.set(new Vector3f(0.0f, 1.0f, 0.0f));
    TransformGroup leafXfmGrp = new TransformGroup(leafXfm);
    //Create the leaves
    Sphere myLeaf = new Sphere(0.5f, leafApp);
    //Add the leaves to the leaf group
    leafXfmGrp.addChild(myLeaf);
    //Add the leaf group to the tree group
    treeXfmGrp.addChild(leafXfmGrp);
    //Create another tree
    Transform3D tree1Xfm = new Transform3D();
    tree1Xfm.set(new Vector3f(1.4f, 0.0f, -0.5f));
    TransformGroup tree1XfmGrp = new TransformGroup(tree1Xfm);
    Cylinder myTrunk1 = new Cylinder(0.1f, 1.0f, trunkApp);
    tree1XfmGrp.addChild(myTrunk1);
    Transform3D leaf1Xfm = new Transform3D();
    leaf1Xfm.set(new Vector3f(0.0f, 1.0f, 0.0f));
    TransformGroup leaf1XfmGrp = new TransformGroup(leaf1Xfm);
    Sphere myLeaf1 = new Sphere(0.5f, leafApp);
    leaf1XfmGrp.addChild(myLeaf1);
    tree1XfmGrp.addChild(leaf1XfmGrp);
    //Create the final tree
    Transform3D tree2Xfm = new Transform3D();
    tree2Xfm.set(new Vector3f(1.2f, 0.0f, 1.0f));
    TransformGroup tree2XfmGrp = new TransformGroup(tree2Xfm);
    Cylinder myTrunk2 = new Cylinder(0.1f, 1.0f, trunkApp);
    tree2XfmGrp.addChild(myTrunk2);
    Transform3D leaf2Xfm = new Transform3D();
    leaf2Xfm.set(new Vector3f(0.0f, 1.0f, 0.0f));
    TransformGroup leaf2XfmGrp = new TransformGroup(leaf2Xfm);
    Sphere myLeaf2 = new Sphere(0.5f, leafApp);
    leaf2XfmGrp.addChild(myLeaf2);
    tree2XfmGrp.addChild(leaf2XfmGrp);
    //Put the scene together by adding all the groups
    //to the scene group
    theScene.addChild(house);
    theScene.addChild(treeXfmGrp);    theScene.addChild(tree1XfmGrp);
    theScene.addChild(tree2XfmGrp);
    return theScene;
  }

  /**
   * Handles the exit button action to quit the program.
   */
  public void actionPerformed(ActionEvent e) {
    dispose();
    System.exit(0);
  }

  public SimpleCombine() {
    VirtualUniverse myUniverse = new VirtualUniverse();
    Locale myLocale = new Locale(myUniverse);
    myLocale.addBranchGraph(buildViewBranch(myCanvas3D));
    myLocale.addBranchGraph(buildContentBranch(buildShape()));
    setTitle("SimpleWorld");
    setSize(400, 400);
    setLayout(new BorderLayout());
    add("Center", myCanvas3D);
    add("South", myButton);
    myButton.addActionListener(this);
    setVisible(true);
  }

  public static void main(String[] args) {
    SimpleCombine sw = new SimpleCombine();
  }
}