For this chapter, you will need to use Unity 4.6 or later. At the time of writing, Unity 4.6 is available in beta, which can be downloaded from http://unity3d.com/unity/beta/4.6. Specifically, I used Unity 4.6 Beta 17.

Though I have experienced no problems with the Unity 4.6 Beta version, it's recommended that you do not use it for content you plan to ship soon, and it can be used for testing purposes only, but the steps that I take in this chapter should carry over when 4.6 is officially released.

That being said, I do recommend installing both the stable version of Unity and the Beta version. However, if you just run the Unity Beta installer, it will overwrite your previous version. For information on installing multiple versions of Unity, check out http://docs.unity3d.com/Manual/InstallingMultipleVersionsofUnity.html.