Recognize (Harware)Objects on the screen

[Spunk]

Heyho,

first, please ignore my grammar mistakes, I don´t write perfect english.

What I want to know:
Is it possible to recognize Objects like a little Stone (and it´s heaviness) that I put on to the screen in objective C? So not a gesture recognizer but something similar to it.

I thought of coding a game with real tokens to put on the screen that have different weights.


Thank you