Author Topic: Multimarker Tracking  (Read 1670 times)

tomroesi

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Multimarker Tracking
« on: April 27, 2011, 08:39:05 pm »
Hello,

i have a problem with the Build AR Pro 2 and the multimarker tracking.
How schould i setup the tracker to work?
I use the multi.dat and the "abcdef" marker but nothing works.

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Giles Westerfield

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Re: Multimarker Tracking
« Reply #1 on: April 30, 2011, 06:50:13 pm »
Hello,

Sorry for the lack of explanation regarding multi-markers in the help documentation. They are a somewhat advanced feature that can be little tricky to set up.

A multi-marker is simply a group of normal (single) markers that are treated as if they are a single marker. Multi-markers can be useful for scenes where parts of the marker may be occluded for any reason. As long as at least one of the single markers on the multi-marker is visible, the marker will still be tracked properly.

To create a multi-marker, you will first need a regular pattern file for each of the single markers that are part of the multi-marker. Then you will create a special .dat file that tells BuildAR the locations of the pattern files and how they are positioned relative to each other on the multi-marker.

The .dat file is just a normal text file, and you can create it using a text editor like Wordpad. The format of the .dat file is explained in this image:

http://www.hitl.washington.edu/artoolkit/documentation/images/multiconfigfile.jpg

I've attached an archive to this post containing a sample multi-marker .dat file along with the individual pattern files. You can edit the .dat file to use your own pattern files. Please note that the paths to the pattern files in the .dat file need to be relative to the BuildAREditor executable.

The transformation matrix part of the .dat file entries may seem confusing, but you only need to worry about the last column of numbers if the patterns are all facing the same direction. From top to bottom, the top three numbers of the last column of the transformation matrix represent the x,y,z position (in mm) of the current pattern file relative to the origin of the marker. You don't need to worry about changing these numbers if you are using the same layout for your multi-marker.

Let me know if you need more help with multimarkers. My guess is that you do not have the correct file paths in the multi.dat file. Make sure the the file paths to each of the "abcdef" patterns is relative to the BuildAR executable.

Cheers,

Giles
BuildAR Pro Developer
Human Interface Technology Lab New Zealand
www.hitlabnz.org

evansjaw

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Re: Multimarker Tracking
« Reply #2 on: September 13, 2011, 09:20:58 am »
I tested your multi marker example and a modified one of my own. This feature currently does not work. multi.dat does not load when you hit ok on the "Add ARToolKit Marker" dialogue box. Nothing loads. Should it not be a dat? Can you give an example where it does work? Im rather disappointed because this is one of the functionalities that I bought your product for.

If you do go back in and fix it, It would be great to give it "cases". ie:

case1:
A,B,C visible not D

case2:
A,B,D visible not C

nicomurillo

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Re: Multimarker Tracking
« Reply #3 on: September 30, 2011, 08:34:18 am »
The folder is renamed to multi (not multi-marker) and placed in the data folder, not markers.

But how to make two markers interact with each other?

 and

If you do go back in and fix it, It would be great to give it "cases". ie:

case1:
A,B,C visible not D

case2:
A,B,D visible not C