Interaction of iPad display and physical object?

Question

iPad

I saw a toy based on the cartoon "Cars" in the top of the app store . The interesting thing is that you can use a toy car to control the gameplay by sliding it across the screen. The material used is apparently similar to that used in styluses for capacitive screens (a la conductive rubber).
Hence the question - how can this be implemented - does the touch display determine the shape of the print, for example? How can this be tested - are there any corresponding eppa?

Answer 1

Perhaps you will find the answer here: habrahabr.ru/blogs/personal/132961/#comments

Answer 2

No, the touch does not determine the form. To determine the shape, you need to have several touch points on the object (4-piece car wheels), again, the display is unaware of the coloring of the object, on the video, most likely the same several surfaces separated from each other for the display reaction (points in the corner of the maps or something else hidden on touch side of the display)