Determining the shape of an object that can change dynamically is a bit of a challenge, one that especially scares those who are really into virtual reality. Sensing the orientation of various limbs and appendages usually requires external sensors such as cameras, or limits the focus to specific details such as just the player’s hands and fingers. A more comprehensive and potentially flexible approach could be possible with optical waveguides, as demonstrated by [Qifan Yu] et al. in a recent article and Advanced intelligent systems.
Waveguides are structures that guide electromagnetic waves, with optical waveguides like the one used here to target EM radiation in the optical band. This may even allow the use of cheap and abundant optical fiber, although custom elastomeric waveguides are manufactured here. These are placed on the sheet in a double-sided, overlapping zig-zag pattern, which allows a simple reconstruction of the shape of said sheet based on how the wave propagation through the waveguide changes.
By characterizing the behavior of the signals through the waveguide, its shape and thus that of the sheet can be reconstructed. This was then proven correct by wrapping the sheet around the arm of a volunteer, elow and hand, detecting the flexion and movement of individual joints.
Although quite bulky in the demonstrated configuration and with an unoptimized algorithm, it is probably something that can be miniaturized to the point where it can be woven into regular fabric. This could make for sensor blades that track the configuration of everything from robots to human bodies for something like VR purposes.