1. A method, comprising: presenting, by a computer, multiple interactive items on a display driven by the computer; receiving, from a depth sensor, a sequence of three-dimensional (3D) maps containing at least a hand of a user of the computer; defining an interaction surface in space in proximity to the user; detecting in the maps a transverse motion of the hand in space, and positioning, on the display, a cursor in response to the transverse motion; detecting, in the maps, a select gesture performed by the hand and directed toward one of the multiple interactive items while the hand engages the interaction surface; and distorting a region on the display containing the one of the multiple interactive items in response to the select gesture and engagement of the interaction surface by the hand, by presenting the region surrounding the cursor as a recessed vertex.