A method for carving a 3D space using hands tracking is described. In one aspect, a method includes accessing a first frame from a camera of a display device, tracking, using a hand tracking algorithm operating at the display device, hand pixels corresponding to one or more user hands depicted in the first frame, detecting, using a sensor of the display device, depths of the hand pixels, identifying a 3D region based on the depths of the hand pixels, and applying a 3D reconstruction engine to the 3D region.