private void setupKeys() {
        flyCam.setMoveSpeed(50);
        inputManager.addMapping("wireframe", new KeyTrigger(KeyInput.KEY_T));
        inputManager.addListener(actionListener, "wireframe");
        inputManager.addMapping("Lefts", new KeyTrigger(KeyInput.KEY_H));
        inputManager.addMapping("Rights", new KeyTrigger(KeyInput.KEY_K));
        inputManager.addMapping("Ups", new KeyTrigger(KeyInput.KEY_U));
        inputManager.addMapping("Downs", new KeyTrigger(KeyInput.KEY_J));
        inputManager.addMapping("Forwards", new KeyTrigger(KeyInput.KEY_Y));
        inputManager.addMapping("Backs", new KeyTrigger(KeyInput.KEY_I));
        inputManager.addListener(actionListener, "Lefts");
        inputManager.addListener(actionListener, "Rights");
        inputManager.addListener(actionListener, "Ups");
        inputManager.addListener(actionListener, "Downs");
        inputManager.addListener(actionListener, "Forwards");
        inputManager.addListener(actionListener, "Backs");
        inputManager.addMapping("shoot", new MouseButtonTrigger(MouseInput.BUTTON_LEFT));
        inputManager.addListener(actionListener, "shoot");
        inputManager.addMapping("cameraDown", new MouseButtonTrigger(MouseInput.BUTTON_RIGHT));
        inputManager.addListener(actionListener, "cameraDown");
    }
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