Hi there,


Is there a good example on how to do multiple cams in ar toolkit?
The twoView.c example does not work for me.

When I use 1 cam with twoView, it works, but if I use 2 cams,
I get an error on an incompatible mode for the 2nd cam.

This error is bogus, because the two cams are exactly the same,
and for both cams I use exactly the same configuration. So
ARtoolkit's claim on an incompatible mode cannot be correct.

Also, twoView.c is a lot of code, compared to simpleTest.c
Isn't there a more elegant method of using multiple cams?

thanks,

 Bram Stolk

-- 
Bram Stolk, VR Engineer SARA, Amsterdam.   tel +31 20 592 3000

"Windows is a 32-bit extension to a 16-bit graphical shell for an 8-bit
 operating system originally coded for a 4-bit microprocessor by a 2-bit
 company that can't stand 1 bit of competition."

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hi Bram,

what do you want to do with the two cameras?
just tracking of two cameras or real stereo tracking?

bye,
Daniel


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Daniel Wagner wrote:
> hi Bram,
> 
> what do you want to do with the two cameras?
> just tracking of two cameras or real stereo tracking?
> 
> bye,
> Daniel
> 

See my previous mail on camera/viewpoint decoupling.
I want to do something like this:

http://homepages.cwi.nl/~robertl/pss/pss.html

So, tracking of 1 or more objects, with multiple cameras,
and there is no HMD involved.

  Bram


-- 
Bram Stolk, VR Engineer SARA, Amsterdam.   tel +31 20 592 3000

"Windows is a 32-bit extension to a 16-bit graphical shell for an 8-bit
 operating system originally coded for a 4-bit microprocessor by a 2-bit
 company that can't stand 1 bit of competition."

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Bram Stolk wrote:

>So, tracking of 1 or more objects, with multiple cameras,
>and there is no HMD involved.
>  
>
if i got you correct then all you want to do is have multiple instances
of ARToolKit running to get independent tracking results from several
cameras .  you want to merge these tracking results on your own (called
"averaging" in your prev. email).

so one problem could be the support for multiple cameras with the camera
library that comes with ARToolKit (i don't use that and can not comment
on it). this is a problem seperate of the tracking itself and should one
way or the other no real problem to solve. as you work in the VR area
you probably have enough knowledge such issues.

the main problem i see here is that ARToolKit uses lots of static
variables internally which produces problems since the history of the
multiple cameras would be mixed together. i see two simple, clean solutions:
- use ARToolKit in seperate processes for each camera
- use ARToolKitPlus which allows you to use completely seperate tracker
instances for each camera

Daniel


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I think ARToolKitPlus is the best option. It is very easy to use.=20
As Daniel Wagner said, ARToolKit in seperate processes for each camera
can be another solution but I think that it is uglier and more
complicated :)

-----Original Message-----
From: owner-artoolkit@h ..................
[mailto:owner-artoolkit@h ..................] On Behalf Of Daniel Wagner
Sent: martes, 13 de diciembre de 2005 16:56
To: ARToolkit
Subject: Re: twoView.c and multiple cameras in AR toolkit

Bram Stolk wrote:

>So, tracking of 1 or more objects, with multiple cameras,
>and there is no HMD involved.
> =20
>
if i got you correct then all you want to do is have multiple instances
of ARToolKit running to get independent tracking results from several
cameras .  you want to merge these tracking results on your own (called
"averaging" in your prev. email).

so one problem could be the support for multiple cameras with the camera
library that comes with ARToolKit (i don't use that and can not comment
on it). this is a problem seperate of the tracking itself and should one
way or the other no real problem to solve. as you work in the VR area
you probably have enough knowledge such issues.

the main problem i see here is that ARToolKit uses lots of static
variables internally which produces problems since the history of the
multiple cameras would be mixed together. i see two simple, clean
solutions:
- use ARToolKit in seperate processes for each camera
- use ARToolKitPlus which allows you to use completely seperate tracker
instances for each camera

Daniel

Hello,

I am sorry I can't help.
but I also want to voice that I also experience similar error when
running twoView sample.
The second camera won't work, and I don't know why. It is exactly the same =
type.
I actually also tried with two different type, and it also didn't work.

Anybody managed to get twoView example running?

(btw, I am using Windows)

Ron

On 12/14/05, Bram Stolk <bram@s ......> wrote:
> Hi there,
>
>
> Is there a good example on how to do multiple cams in ar toolkit?
> The twoView.c example does not work for me.
>
> When I use 1 cam with twoView, it works, but if I use 2 cams,
> I get an error on an incompatible mode for the 2nd cam.
>
> This error is bogus, because the two cams are exactly the same,
> and for both cams I use exactly the same configuration. So
> ARtoolkit's claim on an incompatible mode cannot be correct.
>
> Also, twoView.c is a lot of code, compared to simpleTest.c
> Isn't there a more elegant method of using multiple cams?
>
> thanks,
>
>  Bram Stolk
>
> --
> Bram Stolk, VR Engineer SARA, Amsterdam.   tel +31 20 592 3000
>
> "Windows is a 32-bit extension to a 16-bit graphical shell for an 8-bit
>  operating system originally coded for a 4-bit microprocessor by a 2-bit
>  company that can't stand 1 bit of competition."
>