Killer Game Programming in Java

Scenery Creation

WrapTerra3D sets up the lighting and background, creates a Landscape object, and initializes the KeyControl object for managing user navigation. The background code sets the sky to be medium blue, with stars added to its geometry:

    private void addBackground()
    { Background back = new Background();
      back.setApplicationBounds( bounds );
      back.setColor(0.17f, 0.50f, 0.92f);
      back.setGeometry( addStars() );
      sceneBG.addChild( back );
    }

The background geometry can be any type of Group node, but there are some restrictions on the shapes held inside the group. For example, Shape3D is fine, but OrientedShape3D is prohibited. The geometry is restricted to a unit sphere but drawn as if located at infinity.

addStars() creates a PointArray of coordinates at random places in the hemisphere above the XZ plane (there's no reason to have stars below the horizon). The colors of the points are randomly chosen:

 private BranchGroup addStars() { PointArray starField = new PointArray(NUM_STARS, PointArray.COORDINATES | PointArray.COLOR_3); float[] pt = new float[3]; float[] brightness = new float[3]; Random rand = new Random(); for (int i=0; i < NUM_STARS; i++) { pt[0] = (rand.nextInt(2) == 0) ? -rand.nextFloat() : rand.nextFloat(); pt[1] = rand.nextFloat(); // only above the XZ plane pt[2] = (rand.nextInt(2) == 0) ? -rand.nextFloat() : rand.nextFloat(); starField.setCoordinate(i, pt); float mag = rand.nextFloat(); brightness[0] = mag; brightness[1] = mag; brightness[2] = mag; starField.setColor(i, ...