Disney Research's new 3D touch surfaces technology allows people to feel what is on their screens. This means users can feel simulated textures through their tablet, phone or computer touch screens. This involves virtual 3D bumps, so one can feel a jellyfish without getting stung or outline the ridges in a map. This can be done using an algorithm that measures things like friction and voltage.
The technical details behind the algorithm behind the 3D touch surfaces can be found in a research paper. There are three main steps: calculating the gradient of the desired surface; determining the 'dot product' of the surface's gradient as well as the velocity of the sliding finger; and mapping the dot product to the voltage.