Hi Teis,
This might help you: A reply of Kato to a previous query.
Kasim
----- Original Message -----
From: "Hirokazu Kato" <kato@s ........................>
To: "Stuart" <stuart@t ............>
Cc: <artoolkit@h ..................>
Sent: Thursday, October 03, 2002 5:17 AM
Subject: Re: Position tracking
> Hi,
>
> >What I'm asking is this: am I correct in thinking that it's possible to
> >use the libraries to determine the camera's position given that you know
> >the exact positions of the markers?
>
> Actually, ARToolKit calculates marker position in camera coordinates
> by 3x4 transformation matrix. In order to get cmera position in marker
> coordinates, you have to invert the matrix. This inverted matrix
represents
> transformation from camera to marker. therefore translation component of
the
> matrix means camera position in marker coodinates.
>
> >Am I also correct in thinking that arDetectMarker() and arGetTransMat()
> >will enable me to extract the positional data of the camera, given that I
> >know the locations of the markers in the physical world?
>
> You have to take care of the accuracy.
> Basically ARToolKit is designed for image overlay.
> It is not designed for 3D measurement system.
> Anyway you have to calibrate your camera very carefully.
>
> --
> ------------------------------------------------------------------
> Hirokazu Kato
> Faculty of Information Sciences
> Hiroshima City University Phone: +81-82-830-1705
> Email: kato@s ........................ Fax: +81-82-830-1435
> URL: http://www.sys.im.hiroshima-cu.ac.jp/people/kato/
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