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Giving our screens greater depth

Will we one day be able to appreciate the soft texture of a fabric using the Internet? INRIA and CNRS researchers are working on technology to enable computer users to feel surface contours.1 By combining haptic processes and images, the team led by Anatole Lécuyer, a researcher at the IRISA laboratory in Rennes (Brittany, France), has managed to reproduce tactile perception, letting users 'feel' holes and bumps that appear on a screen with their computer mouse.2

 “Haptic” or “force feedback” interfaces are well known to video game enthusiasts. They are used to reproduce specific physical sensations relating to the onscreen action by means of motors moving in opposite directions. A force feedback steering wheel or joystick imitates the resistance effects associated with driving a racecar or flying an airplane in one or even two dimensions, whereas a “haptic arm” goes even further by allowing users to manipulate virtual objects in three dimensions.

 Despite the increasing amount of energy and resources spent on development, none of the current devices can perfectly replicate actual tactile sensations. Indeed, computers are still unable to faithfully render the impression gained by running a finger over a surface! Designing cost-effective, user-friendly technology which achieves this is no simple matter. Yet that is exactly what Lécuyer and his colleagues have succeeded in doing. This team of computer scientists set out with the simple idea that it is easier to manipulate a familiar device than to learn how to use a new piece of equipment. Consequently, their process involves the computer's mouse and the familiar action of moving the cursor across the screen. What's different, though, is the speed. With Lécuyer's mouse, the speed of the cursor varies according to its current position on the uneven surface, the image of which is displayed on the screen. Under normal circumstances, the cursor moves smoothly, but as soon as its tip encounters the slope of a virtual “bump,” it moves more slowly until it reaches the “summit.”  Similarly, a downward slope is simulated by an accelerating cursor. Finally, a sudden stop in cursor movement is used to depict arriving at a “wall.”  IRISA's researchers can thus enable a person in front of a screen to feel surface variations such as bumps and depressions.3

 Better still, “the tests that we have carried out on volunteers have shown that the cursor alone is enough of a cue,” explains Lécuyer. “Even when the image of the surface does not appear on the screen, users are capable of recognizing a bump or a depression by watching the cursor's movement.”  This innovative technology is easily assimilated, which helps broaden its scope to an even larger number of potential applications: in addition to enhancing video games and other recreational activities, the fields affected range from touching up images and photos to cartography. Virtual depressions could also be added to pull-down menus to make them easier to use. On a web page, the technology can draw attention to an advertisement or highlight the most appropriate information during a search. Fabric manufacturers have already expressed their interest in using the technology to sell textiles over the Internet...

Vahé Ter Minassian

Notes :

1. National Institute of Research in Computer Science and Control.
2. Institute of Research in Computer Science and Random Systems. Joint lab: CNRS / University of Rennes / INRIA / Insa Rennes.
3. You can test the different surfaces displayed on the screen at View web site

Contacts :

Anatole Lécuyer
IRISA, Rennes


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