Animate / Fade Intensity

let animation2 = CAKeyframeAnimation()

animation2.keyPath = "geometry.firstMaterial.diffuse.intensity"

animation2.values   =  [2, 0.2, 0.1, 0]

animation2.keyTimes =  [0, 0.5, 0.9, 3]

animation2.duration =  3

animation2.isAdditive = false

self.addAnimation(animation2, forKey: "test2")