In a diploma project at hyperwerk.ch we have been working extensively with
ARToolKit. Basically our application called Augmented Chemistry allows you
to 'build' molecules using a set of tools while sitting in front of a
mirror-like projection/camera-setup. Every tool is based on ARToolKit.
All the code will be open source (including addtl. API e.g. ACObjectCube
that can be used as a very stable 3D-mouse providing you a quaternion of the
current state etc. // chemistry-specific implementations e.g. check for
isomorphism between several molecules // Simple filtering routines to make
ARToolKit more stable // etc.etc.)
We didn't announce all of this yet, but there will be soon more details. For
a quick overview please download the follwing QuickTime-Movie (danger: 12.9
MB!) - you'll see the setup and all the features.
To answer your question: ARToolKit just gives you a 4x4
transformation-matrix, nothing more. the rest is game programming :-). Set
two different markers, play with the matrices in the mainloop, look at the
numbers and you will quickly understand how to build something more complex.
For distances between markers, you can use x,y,z-translation in matrix,
matrix, matrix of the corresponding marker.
If you're planning to play around with more complex interactions you should
define your own API-layer on top of ARToolKit as soon as possible.
> in AR-Toolkit virtual objects can interact. That means, when two
> markers have a specific distance then something is happening on the
> virtual objects.
> Has anybody of you an example-source how to implement an interaction or
> an idea where to get it?