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Detecting multiple markers

By ayazalavi on Wed, 08/08/2012 - 10:26

Hi,

 

I have 2 markers that will be present at the same time on user screen. I want to detect both of these markers and do some calculations. Current Multitarget sample project detect only one marker at a time so even if we have 2 markers present in front of camera, it will return us 1 for state.getNumActiveTrackables().

 

How will I be able to detect 2 markers at the sametime and also get projection and matrices for them.

 

Thanks

 

It is surprising to me that we can not track more than one MultiTarget. I have a setup where I have two MultiTargets, that I can track simultaneous, but it will only detect them and start tracking under special circumstances.

Hi perb,

After discussions with the dev team, can you try setting max simultaneous targets to 7, and then 12 to see if it makes a difference?

Please keep me informed here.

thanks,

N

Hi Nalin,

thank you for your reply. I had already tried different values for the "Max Simultaneous Image Targets". Now I have done some more tests and it seems it has to do with the multitargets I have set up.

I modified the XML file that defines the targets and set up a couple MultiTarget that has ten parts and that is also where I defined the orientation to describe a circle. I thought this was the preferred way to set up MultiTargets.

Is that not supported?

Hi perb

I think there is an internal limit at the moment.

Could you try with a 9 part multi-target?  ..as 10 might be the magic number ;)

N

It does look to be the case. Is 9 parts in a multi target the limit or is the 18 imagetargets in total the limit.

Could I still do 9 parts, if I wanted to track 3 targets?

Is there any way to change that magic number or is that hardcoded?

I think at present it is 9 parts per multi-target, and if you wanted to track 3 targets I can only suggest that you try it and see.

At present this is hardcoded, and thank you for bringing it to our attention as it will be fixed in a future release.