The Interactive Tag Playground (ITP) is an instrumented open space that allows for interactive play, more images and Dutch info can be found on the COMMIT/ IUALL project webpage. Several players are tracked and their movements are analyzed and form the basis of several game mechanics. We use a floor-projection to visualize each player’s role, but also add novel interactive elements such as power-ups and bonuses. The ITP is more than entertainment, it doubles as a tool to record and study how people interact with each other and the environment. Our final aim is to automatically steer the interactions in such a way that all players remain engaged and physically active.
We use two computers, one for tracking the players and one for running the game. The game is run at a 1920*2400 pixels using two wide angle projectors. The tracking is based on the depth channels of 4 Kinects. Using a smart calibration process the non-active areas are cut away and after detection of the players the four areas are put together to track the players. Using appropriate filters and right set of underlying assumptions, we created a sturdy tracking system.
Using smart networking connections we have diminished lag, can automatically start everything by simply putting the power and projectors on. The network setup also allows us to have multiple computers accessing the tracking information and we are now even working on a distributed version of playing tag (people playing ‘together’ at different locations).
Steering gameplay behavior
With the introduction of the technology we can now measure and influence the game. This could allow the playground to detect players that are not really participating or are having a hard time to tag someone. We don’t want to even the game completely. We do like to provide a pleasant experience in which we might prevent teasing and taunting turning into bullying or fights. To show some of these possibilities we did user tests with students at the university. For instance, based on the automatic measurements of the time someone has been the tagger, we changed the size of the circles. Making it easier for the players that had a hard time, by giving them a bigger circle as a tagger, and making it harder for the good players giving them a bigger circle as a runner compared to the other runners. Our results showed that the time students were the tagger indeed evened out more in this version. It also indicated to us that groups in which someone was unable to tag others for a long time (had a small injury) suddenly were better able to play the game with such an intervention.
We also showed that pointing someone out with an arrow increases the chances that this person becomes the tagger, even if it is allowed to tag the other players as well. Therefore, we have created a version with arrows always pointing at the player being the tagger the shortest amount of time.
In another version of the game we added power-ups. We tried to get people to move to different places than they would normally visit, which in turn could increase the amount they walked or support players to get into contact with each other. In our analyses we did see students gathering these power-ups but they wouldn’t stick around for long enough to find any real differences. However, most students preferred such a version and we think that the introduction of these elements might increase the engagement. Therefore, a future concept is to use measurements of total distance walked, that could be indicative for a drop in engagement and then at these moments of lowered engagement let power-ups appear to re-engage the players.
With the data we got from workshops we did with hundreds of children, we are looking whether children were tempted to go towards the tagger if there is a bonus, by steeling small balls from the tagger they can make a circle prettier or win a shield. Will children take this “risk” of getting closer only for the reward of added “swag”? Or do they take this “risk” more often if they get a shield? With such an intervention to stimulate risk taking, we might also diminish the time someone is a tagger in an adaptive way, Furthermore, we believe this to be a less obtrusive way to do this than directly changing the circle’s size.
Regulating physical activity
One of the goals of interactive playgrounds can be to stimulate physical activity. Measuring the amount of physical activity can be a tedious task that often requires annotation or the use of sensors that need to be worn. Using the automatic recognized positions of the players we were able to measure the physical activity of the players. We also showed that we could change this amount of physical activity by changing the size of the players’ circles. In the future this can help in regulating the pace of the game in order to efficiently stimulate physical activity.
Type of users
We have had a variety of players, all with a very positive response. Our early experiments included students playing vigorously. During the exposition we had parents with children playing, we had some toddlers walking on the playground, there were some teenagers, and even heard of a grandfather playing with his child. During the workshops there were children from primary schools, mainly in the ages eight to twelve years old. During these workshops part of the group was sitting down as observers. They had an active role making suggestions for the players and supporting players. We did see that the younger children (approx 2-5) were too impressed by the graphics or had a hard time to grasp the game mechanics, for this age group it would be harder to steer during game play.