Chris
Harrison

LightAnchors: Appropriating Point Lights for Augmented Reality Interfaces

Augmented reality (AR) allows for the overlay of digital information and interactive content onto scenes and objects. In order to provide tight registration of data onto objects in a scene, it is most common for markers to be employed. Innumerable visual tagging strategies have been investigated in both academia and industry (e.g., retroreflective stickers, barcodes, ARToolKit markers, ARTags, AprilTags, QR Codes and ArUco markers).

In this paper, we present LightAnchors, a new method to display spatially-anchored data in augmented reality applications. Unlike most prior tracking methods, which instrument objects with markers (often large and/or obtrusive), we take advantage of point lights already found in many objects and environments. For example, most electrical appliances now feature small (LED) status lights, and light bulbs are common in indoor and outdoor settings. In addition to leveraging these point lights for in-view anchoring (i.e., attaching information and interfaces to specific objects), we also co-opt these lights for data transmission, blinking them rapidly to encode binary data.

Another difference from conventional markers is that LightAnchors can transmit many simultaneous and dynamic payloads, without the need for WiFi, Bluetooth or indeed, any connectivity. Devices need only an inexpensive microcontroller with the ability to blink a LED. This could allow “dumb” devices to become smarter through AR with minimal extra cost (<$1). For example, we created a glue gun that transmits its live temperature. For devices that already contain a microprocessor, LightAnchors opens a new information outlet in AR, for example, the LED found in many security cameras could be used to share the device’s privacy policy.

Download

Reference

Ahuja, K., Pareddy, S., Xiao, R., Goel, M. and Harrison, C. 2019. LightAnchors: Appropriating Point Lights for Spatially-Anchored Augmented Reality Interfaces. In Proceedings of the 32st Annual ACM Symposium on User Interface Software and Technology (New Orleans, USA, October 20 - 23, 2019). UIST '19. ACM, New York, NY.

© Chris Harrison