Interactive floor projections: how to?

[ethernal]

First of all, I didn't know where to put this post. I did it here because I'll implement this on AS3. If it's wrong, please move it to the right place.

Well, I've been requested to do some interactive pieces like these:

<http://www.youtube.com/watch?v=1xYg3BNjm5w&feature=related> (http://www.youtube.com/watch?v=1xYg3BNjm5w&feature=related)
<http://www.youtube.com/watch?v=--gACt4x1kA&feature=related> (http://www.youtube.com/watch?v=--gACt4x1kA&feature=related)
<http://www.youtube.com/watch?v=JiUeqicgYUA&feature=related> (http://www.youtube.com/watch?v=JiUeqicgYUA&feature=related)

It has a projector on the ceil, and the events are generated by the shadows. The client told us that we have to do it with mouse events. What I don't understand is if they are mouse events, what happens when there are multiple users casting shadows at the same time? How does a "shape" (the shadow) generate mouse events?

[jwopitz]

Does the client understand really what they are telling you? That makes no sense really. The only thing I can think of is that there might be some sort of method for finding the relative center point of the shadow and assigning the mouse position to that center point. Even that doesn't address the fact that these videos are showing quite a bit of multitouch functionality. That is unless the program is only paying attention to those shadows in motion. On the soccer one, only the moving shadow is the shadow that hits the ball, not the planted foot.

Regarding the term mouse event, I would think the client is speaking more abstractly in terms of how they were planning to hook up information from the user to the computer, not specifically speaking on how the flash player interprets them. If indeed you only need to work with one point of interaction at one time, you probably won't have any issue with interpreting for the flash player. However if you need to handle multiple points of interaction at the same time, you might need to take a look at hooking up some sort of multi touch java API to communicate information to the flash player. I would also check out Processing to see if it already has some of this support. Processing is a really cool API based on Java. I have used it a few times.

I haven't looked at this in a long time just because multitouch and flash required that extra hook up. Cool installation project nonetheless. Hope you get some leads. Keep us posted though as I am really interested in how your project turns out.

[jwopitz]

check this out. Its not using mouse events at all, but maybe you could present this to your client as this is generally the way this is done - http://labs.ideo.com/2008/08/15/our-home-brew-multi-touch-system/

It uses the concept of FTIR (I think)
http://cs.nyu.edu/~jhan/ftirsense/
http://en.wikipedia.org/wiki/Total_internal_reflection

[ethernal]

Thaks mate, your links and info look very useful. The first thing I'm gonna do is take a look deeper to them this weekend to be prepared when we waltk to the client next week.

I will keep you informed ;)