Photo: Air Racket
Haptic VR inventors are not running out of ideas: A racket grip drilled with a jet of compressed air should enhance the feel of the ball in virtual racket sports such as tennis.
Although current VR controllers can simulate some rackets quite well, this works credibly, especially for racket sports with fairly gentle ball touches such as golf, table tennis or badminton.
But the subtleties like the hardness or the angle of attack that experienced athletes can feel in reality and take into account in their game are lacking in VR simulations. Racket sports with harder, bigger balls like tennis or baseball also lack the power.
Air pressure for realistic VR haptics
Researchers at the National Taiwan University in Taipei are trying to recreate this complex feeling and stronger force with a fine-tuned air pressure simulation. To do this, they attached an air pressure nozzle to a generic extendable racket handle, which becomes a sport-specific racket in VR.
The compressed air is forced into the nozzle from a portable compressor in a backpack, just as the virtual ball hits the racket. Because the air is expelled in different directions, the system can also simulate the impact angle of the ball.
For tracking, researchers attach an Optitrack system to the tip of the racket handle. Alternatively, a Vive Tracker with SteamVR can take over the tracking job, but it has a higher weight. The air pressure nozzle is a common model for paintball guns.
Optical illusion helps with authentic feeling
As a simulation goal, the researchers took table tennis, badminton and tennis, three of the most popular racket sports, which they wanted to upgrade with a better feel for the ball in virtual reality. Initial tests with subjects showed that the haptic system can increase the immersion and precision of these racket sports.
This also works thanks to an optical trick: the power visualized in VR, especially the length of the shock (350ms vs. 50ms)can make the felt force appear four times stronger than the nozzle actually provides.
The compressor solution is likely to be too expensive for home use, but location-based VR experiences or professional training offers may increase immersion and training effects with such a system.
The researchers offer other 3D-printable stick grips for hockey, golf, baseball, swords and squash. Detailed information about the AirRacket system and code downloads is available on Github.
You can find more unusual haptic ideas for VR behind the link.