We present an approach to alter the perceived appearance of physical objects by controlling their surrounding space. Many real-world objects cannot easily be equipped with displays or actuators in order to change their shape. While common approaches such as projection mapping enable changing the appearance of objects without modifying them, certain surface properties (e. g. highly reflective or transparent surfaces) can make employing these techniques difficult. In this work, we present a conceptual design exploration on how the appearance of an object can be changed by solely altering the space around it, rather than the object itself. In a proof-of-concept implementation, we place objects onto a tabletop display and track them together with users to display perspective-corrected 3D graphics for augmentation. This enables controlling properties such as the perceived size, color, or shape of objects. We characterize the design space of our approach and demonstrate potential applications. For example, we change the contour of a wallet to notify users when their bank account is debited. We envision our approach to gain in importance with increasing ubiquity of display surfaces.
Work will be presented at CHI 2017.
D. Lindlbauer, J. Müller, M. Alexa, 2017. Changing the Appearance of Real-World Objects by Modifying Their Surroundings. CHI ’17, Denver, CO, USA
Download paper in ACM Digital Library (free)
http://dx.doi.org/10.1145/3025453.3025795
For more infos, contact David Lindlbauer (david.lindlbauer[_at_]tu-berlin.de or @da_lind).
In the virtual world, from traditional desktop computing to virtual reality, changing the appearance of objects or interfaces is one of the main means to communicate information. Objects are altered in color for emphasizing them, they are hidden or revealed when needed, or resized to afford manipulation or communicate importance. Objects in virtual environments are easy to modify: research in computer graphics explored creating complex visual changes in real-time, for example through dynamic bump mapping or environment mapping. With the help of these techniques, arbitrary objects and alterations are achieved.
In this work, we propose a different approach. Instead of augmenting objects directly, we change their appearance by altering their surrounding space. This enables changing the appearance of objects without physical modification, and of objects with surface properties unsuitable for projection. This work provides a conceptual design exploration of our proposed approach and an initial proof-of-concept implementation.
We take inspiration from work on visual illusions, which typically alter the perception of an object through other objects that are present in its surroundings, similar to our approach. Furthermore, we build on computer graphics research on how objects are visually altered (e. g. through normal or environment maps). We create optically dynamic objects and con- tribute one additional technique (besides existing techniques such as projection mapping, shape-changing interfaces, and optically dynamic materials) for bridging the virtual and the real world.
Applications
We demonstrate a proof-of-concept realization of our concept with a conventional tabletop display and an optical tracking system. We show the possibility of changing the perceived size, position, contour, color, or visibility of real-world objects. In our current implementation, objects are manually specified by users or are automatically recognized by our system based on predefined marker sets. We employ these effects in three scenarios: as ambient displays, for notifications, and for increased privacy. In the ambient display scenario, the color and position of existing objects (water bottle, medicine box, keys) are changed to communicate status. For displaying notifications, we change the perceived contour of a wallet to get dynamic spikes for indicating bank transactions. Lastly, by displaying colored areas in an object’s surroundings we change its visibility to “hide” it from distant observers for increased privacy (we hide a phone on a user’s desk).
