For all of the people who have seen or played a Metroid Prime Game, I need to ask you a question. How do you think they animate that thing when you change your beam? Please Reply, thanks!
If you mean how the light bends towards the charging beam you could sorta do it with a raytraced ball or dome with 100% transparency and a little IOR, but thats a poor way of doing it.
Sorry, I guess I said that wrong. I ment to say how the gun itself changes when you select a diferent beam. It changes shape. Also, when you are charging the gun, it gets slightly larger. Thanks anyway! 
From what I remember, the gun is made out of different parts that fit together perfectly. When the gun changes, it’s just different parts of the gun poping out, and the color changes. The same goes for when it charges, those parts that are protruding out just slowly go out even further.
It’s a clever design, but it’s really easy to do. They just split the gun up in parts and then pulled those out like pulling blocks out of a Jenga set. If you study it carfully, you can see what they are doing. It probably took them a while to design it, but there was no voodoo that made it work.