Apple recently filed a patent that describes an optical sensor for the next-generation Apple Pencil. The sensor allows the pen to copy the texture and color of the object’s surface. This will help make the light sensor and light emitter. The device will also send this data wirelessly to a laptop computer, allowing it to be used with a drawing program.
Yanko Design has created several renders that show what an Apple Pencil might look like.
Of course, this is just a patent, so it is not yet clear whether such a pen will actually come out.