Object Fade when blocking character

Hello.
I am working on an isometric view game, and well its in a city so it has tall builds.
I need the buildings to fade when blocking the character from the camera.

came across this http://answers.unity3d.com/questions/390473/hide-objects-blocking-character-view.html#answer-390510
but cant get it to work.
I have itween installed, and when watching the camera with that script attached, nothing ever shows up in object field, Ive even tried manually adding an object into that public field and that object still does not fade.

thoughts? or a better way to do this?

 

Maybe the hit distance isn't far enough? It's set to 30, hardwired in the function.

 

tried anywhere from 10 to 1000 on this.