Real world 2 OpenGL

I'm amazed with the accuracy of ARToolkit when drawing OpenGL objects on the
top of video frames. Does somebody knows about references on how was the
process to convert image calculated distances to GL scales? Any idea?

We are writing a small augmented reality system but 3D objects supposed to
be fixed on top seem to slide when patterns are moved.

Thanks.

From:	"Andres Agudelo" <aagudel6@e ...........>	Received:	Jun 4, 2003
To	"ARToolkit" <artoolkit@h ..................>
Subject:	Real world 2 OpenGL
I'm amazed with the accuracy of ARToolkit when drawing OpenGL objects on the top of video frames. Does somebody knows about references on how was the process to convert image calculated distances to GL scales? Any idea? We are writing a small augmented reality system but 3D objects supposed to be fixed on top seem to slide when patterns are moved. Thanks.