@Override
    public void computeLastDistance(Spatial owner) {
        // directional lights are after ambient lights
        // but before all other lights.
        lastDistance = -1; 
    }
Creates a DirectionalLight with the given direction and the given color
@param direction the light's direction
@param color the light's color
jme3-core/src/main/java/com/jme3/light/DirectionalLight.java