Meeting Point - Digital Prisoners

WIP games, tools & toy projects
#1

Thought I’d share a few details of a recent project I’ve been involved in. Whether you’re entirely happy with this being classed as a “game” depends on whether you think all games need to have goals, high-score tables, or be playable on your PC - needless to say, I don’t! :wink:

800×532 56.2 KB

About

At Digital Prisoners we’re interested in creating interactive things for people to play with out in the real world. Meeting Point is a large-scale interactive projection designed for an urban public space. It uses two infra-red cameras mounted at opposite sides of the space, custom computer software and a large-scale projector. The work allows the two participants to interact with each other and, through motion detection, with the other audio and visual elements of each section. For example, the record scratching section allows them to control the spin on screen and the sound of the record by moving from side to side.

lXLmhCwWSNw

Technical Details

Most importantly, it’s Java-based! :slight_smile:

  • This project was built with Praxis LIVE (also in my sig). It is the sort of project Praxis LIVE was designed for.
  • The main projection uses Praxis’ OpenGL pipeline, which uses LWJGL and some (heavily forked) code from libGDX. This makes quite a lot of the custom (live) coding support for GLSL and Java.
  • Video input uses two infra-red CCTV camera, USB capture devices (ran out of PCI slots! :wink: ) and GStreamer bindings. Each video stream is actually split into two using the V4L2loopback module …
  • One stream from each camera goes to the OpenGL pipeline. A second stream from each camera goes into a software pipeline that does motion detection, which is used to pass parameters to control audio and visual elements in each scene.
  • The audio processing is pure Java using Praxis LIVE’s audio FX (most of the effects code is up at https://github.com/jaudiolibs/)
  • The whole thing is projected using a 10,000 lumen Sanyo projector.

If you want to know anything else about the implementation, please ask below.

1600×409 100 KB

I wasn’t sure the best place to post this. Almost put it in Showcase, as it is a finished project and kind of qualifies as a game. However, it doesn’t entirely meet the criteria of “a casual visitor should be able to play your game without any trouble”. Of course, if you’ve got a large space and a spare £4k (projector hire ain’t cheap!) we’d be happy to bring it to you for a few days. ;D

#2

Pretty amazing. Must have been a challenge to connect all those odd bits of technology. Congrats for pulling it off.
Did you have any trouble with vandalism?
Do you think people enjoyed it because it’s similar to the console dance games?
Were people shy to try it?
How does the music work?
Interesting project

#3

Thanks! ;D Not too much of a challenge in that Praxis LIVE was designed for connecting all these odd bits of technology together (mind you, writing that has been a challenge at times! :wink: )

No, but it was well staffed when on site. Also, I think it managed to appeal to those who might otherwise have wanted to cause trouble.

Possibly. It’s not something anyone specifically mentioned, and the age range of people having a go (2~72) might belie that. Our interest is in creating things that are quite playful, intuitive and open-ended - there’s no right or wrong way to play, which is different to the console games I’ve seen at least.

Not for long! Lots of people said there’s no way they’d be up for it, and most were lining up to have a go after 10 min. ;D

Currently the project has five different ‘scenes’, though it’s something we intend to expand on. Three of the scenes don’t have interactive sound, only visuals, and use a variety of sample loops (mostly taken from old tracks of mine) and sequenced somewhat randomly / generatively.

There are two scenes with interactive sound. The record scratching one tracks the horizontal position of the dancer and maps it to the speed and direction of the sample (actually position is mapped to acceleration in speed, which feels more natural). The other scene, which I’m less happy with currently, is in the video between the logos at the end. Each dancer has four ‘strings’ which trigger different guitar samples, and can pluck them from moving back and forth.

That answer your question? This video shows some of the audio stuff in Praxis LIVE, but rather than binding a GUI to parameters, we’re taking movement signals from the video pipelines. NB. This is an oldish video now, some of the editing stuff has been improved recently.

khrOtNN7tN8

#4

Interactive music is pretty cool. It looks well done in your scenes, it doesn’t jar.
Have you seen krasses’ work here? http://www.java-gaming.org/topics/some-reasonable-output-from-my-generative-music-system/27309/view.html

When you were considering what to use for the motion-detection what made you choose infra-red cameras rather than say normal cameras or the xbox kinect os something else?

#5

Thanks. Yes, Krasse’s work is really interesting, though he could really do with using some better sounds. :wink: My interactive or generative stuff tends to be more manipulation of audio data than music / MIDI data.

Interesting question with a somewhat long answer! :slight_smile: We weren’t just using the cameras for motion-detection but also for the live video feed. As the project is designed to work at night (for obvious reasons) we needed to be able to pick up a decent live image, but using a bright spotlight pointing at the person makes it difficult to see the projection as you’re dancing, and I think also makes you feel more self-conscious. Therefore, we used CCTV cameras that have built in infra-red LEDs for illuminating what they’re viewing. These also have the advantage of being robust, waterproof, low-voltage and fairly cheap. The analogue cables for these also have a much better range than USB (though I realise there are ways of extending, or we could have used IP cameras), and the cables also take the power to the camera. The cables we have currently are 18m each, giving us potentially 36m between the cameras with the projector in the middle - this can be extended quite a lot.