How can I detect if a part is visible on-screen?

If you're familiar with the concept of Weeping Angels, this is exactly that.

If not, then I'm wondering if a script can detect whether or not a part is visible on the player's screen and if true, do [blah blah code blah]. And if it is also possible to find where the part is located on screen; whether or not it's near the edge or the center of the field of view, etc.

~Thank ya.