Wrong animation for refractions

[DArnaez]

I made a big mistake. I spend 1 day rendering an animation of a polygon of glass but now I realize that the refractions are the same in the first frame, in the midle or in the end of the movie!!! OHMY!!!! I was thinking that the fact of to use Caustics "from a file" was made for this cases. Wow... can anybody tell me how I can do a render like this that I found in Youtube?

http://www.youtube.com/watch?v=v4xVSOaZg1U

[add101]

The object in the youtube example is animated. Either the object or the light would need to be animated to change the caustics.

[cecofuli]

This is my old tutorial

LINK