var m = { x: 0, y: 0 };
window.addEventListener('mousemove', function (e) {
    m.x = e.clientX;
    m.y = e.clientY;
    camera.position.x = (((m.x / window.innerWidth) * 2) - 1) * -1;
    camera.position.y = ((m.y / window.innerHeight) * 2) - 1;
});