public void loadHintText() {
        BitmapText hintText = new BitmapText(guiFont);
        hintText.setSize(guiFont.getCharSet().getRenderedSize());
        hintText.setLocalTranslation(0, getCamera().getHeight(), 0);
        hintText.setText("Press T to toggle wireframe");
        guiNode.attachChild(hintText);
    }
Creates a terrain object and a collision node to go with it. Then
drops several balls from the sky that collide with the terrain
and roll around.
Left click to place a sphere on the ground where the crosshairs intersect the terrain.
Hit keys 1 or 2 to raise/lower the terrain at that spot.

@author Brent Owens
jme3-examples/src/main/java/jme3test/terrain/TerrainTestCollision.java