var l = {
    colour: 0xffffff,
    intensity: 1,
    distance: 0,
    angle: 10 * (Math.PI/180),
    penumbra: 0.8,
    decay: 1
};

var light = new THREE.SpotLight( l.colour, l.intensity, l.distance, l.angle, l.penumbra, l.decay);
light.position.set(0, 0, 5);
light.target.position.set(0, 0, 1);
scene.add(light.target);
scene.add(light);

var m   = { x: 0, y: 0 };
var pos = { x: 0, y: 0 };

window.addEventListener('mousemove', function (e) {
    m.x = e.clientX;
    m.y = e.clientY;
    pos.x = ((m.x / window.innerWidth) * 2) - 1
    pos.y = (((m.y / window.innerHeight) * 2) - 1) * -1;
    light.target.position.set( pos.x * lightZoom, pos.y * lightZoom, lightZoom );
    light.target.updateMatrixWorld();
});