## Only square capture volume?

studiosapiens
Posts: 6
Joined: Fri Sep 30, 2011 12:47 am

### Only square capture volume?

We have set up our optitrack rig as a rectangle 10 *6 meters in hope that we would get a rectangle capture volume space. But how ever we turn and experiment with the different camera positions and wand the entire space the calibration wizard always shows a cubic volumetric representation aprox. 6*6 instead of 10*6.

Is it a limit in how Arena works that prevent us from accomplish this or are we just doing something wrong?

NaturalPoint - Mike
Posts: 1896
Joined: Tue Feb 01, 2011 8:41 am
Location: Corvallis, OR

### Re: Only square capture volume?

We've definitely set up rectangular volumes in the past, it may just be a visualization issue. Do you get marker tracking throughout the volume? Are capture volume limits set in the point cloud tab (settings)?

simonal
Posts: 14
Joined: Thu Nov 05, 2009 3:07 am

### Re: Only square capture volume?

Hi Mike,

Do you have any best practices for camera setup for rectangular volumes?

NaturalPoint - Mike
Posts: 1896
Joined: Tue Feb 01, 2011 8:41 am
Location: Corvallis, OR

### Re: Only square capture volume?

How many cameras are you using?

Definately put cameras in the corners, then spread the rest over the sides while trying to maintain placement at equal distances. Example: The longer sides should have more cameras than the shorter sides, but the distance between cameras on the short side and cameras on the long side should be as close as possible to maintain a good camera coverage spread.

heath789
Posts: 41
Joined: Wed Aug 10, 2011 7:42 am

### Re: Only square capture volume?

I am trying to do a similar setup. I can get a lot of points during wanding, but the calibration never goes beyond 'poor'.

Are there any special settings for doing a rectangular volume? I have left Single Focal Point as false, assuming that is correct. Any other suggestions for getting a good calibration with this type of capture volume?

Thanks!

18 camera setup, 4 low and 4 high along each side, 1 at each end high in the middle

heath789
Posts: 41
Joined: Wed Aug 10, 2011 7:42 am

### Re: Only square capture volume?

Should have mentioned, we are trying to do about 24'x12' capture volume. Should we maybe try to do 2 capture volumes side by side? Thanks again for your help.

NaturalPoint - Mike
Posts: 1896
Joined: Tue Feb 01, 2011 8:41 am
Location: Corvallis, OR

### Re: Only square capture volume?

What are the dimensions of the rails the cameras are installed on? Could you perhaps diagram an overhead view with distances?

heath789
Posts: 41
Joined: Wed Aug 10, 2011 7:42 am

### Re: Only square capture volume?

I have had some success after downloading the newest version of Arena. It still does not calibrate quickly but it usually gets to the point of being usable.

NaturalPoint - Mike
Posts: 1896
Joined: Tue Feb 01, 2011 8:41 am
Location: Corvallis, OR

### Re: Only square capture volume?

Quick calibration can be a relative term depending on the quantity of cameras as well as the quality. How long is it taking, and what kind of quality are you seeing? A screenshot of the calibration pane right before hitting "apply" would help a bit.

tvining
Posts: 126
Joined: Thu Nov 30, 2006 10:24 am

### Re: Only square capture volume?

I presently have an area 14x20 feet with 8 wide-angle cameras (low and high) in the corners, but I wanted to upgrade to 12 cameras for 2-person capture, as well as to fill in the blind spots on the walls, so I think I will run into similar problems as the above posters. My question is, even with overlapping coverage as you state above, won't the wand keep going in and out of view of some of the cameras, sometimes for long periods while it's down one end of the volume or the other? What will that do to the calibration quality, since normally you try to keep the wand within all the camera capture areas at all times?