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Problems Calibrating
https://forum.ipisoft.com/viewtopic.php?f=6&t=6213		 Page 1 of 2
Author:  ccherrett [ Fri Aug 03, 2012 9:42 pm ]
Post subject:  Problems Calibrating
I am running 2.0.1.138. I just bought a standard license.

i7
32GB RAM,
SSD and raid 0 hard drives
nvidia 550 ti 1GB

I am trying to calibrate my 6 camera setup but everything I try fails to come out with usable results. red and green dots everywhere and barely any sign of the descending spiral I tried to create with my candle mode mag light.

I have also tried the downloadable files from the support section of the website and I get the same results.

Also to note the cameras after auto calibrating their position are in random locations, as well as often upside-down.

I have been trying to get this right for about 12 hours, so I figure it is time to ask for help.

Thanks!
Author:  vmaslov [ Sat Aug 04, 2012 12:29 am ]
Post subject:  Re: Problems Calibrating
Hi
General tips for recording calibration video:
  1. Make the light marker visible to as many cameras as possible all the time. For example, when approaching the perimeter of a capture space, keep the marker inside, so it is not obscured by your body.
  2. Move the marker with a reasonably slow speed, so there are more marker positions in video.
  3. Order cameras in Recorder in the same order they go around capture space. Either clockwise, or counter-clockwise. This would allow to use one of the standard "circle" camera configurations in Studio without (m)any tweaks. Automatic detection of camera positions for more than 4 cameras works good only if initial camera positions have correct order (corresponding to a video).
Author:  ccherrett [ Sat Aug 04, 2012 11:23 am ]
Post subject:  Re: Problems Calibrating
vmaslov wrote:
Hi
General tips for recording calibration video:
  1. Make the light marker visible to as many cameras as possible all the time. For example, when approaching the perimeter of a capture space, keep the marker inside, so it is not obscured by your body.
  2. Move the marker with a reasonably slow speed, so there are more marker positions in video.
  3. Order cameras in Recorder in the same order they go around capture space. Either clockwise, or counter-clockwise. This would allow to use one of the standard "circle" camera configurations in Studio without (m)any tweaks. Automatic detection of camera positions for more than 4 cameras works good only if initial camera positions have correct order (corresponding to a video).


I repositioned my cameras and got better results but some of the cameras after auto calibrate are still in weird spots. I did one calibrate that camera 1,2,3 were perfect but camera 4 was off and that I think throws off camera 5 and 6.

I can see my markers in most cameras at most times, but one camera is sitting on an angle and not tilted a bit, does that matter? Also in previous tries sun shone into a window and stole my markers :)

Before calibrating I reset the cameras to reverse clockwise full circle.

I attached an image of what the calibrate looks like now.

Do you see anything else I could be doing wrong?

Thanks!

Attachments:
calibrate.png
calibrate.png [ 254.29 KiB | Viewed 18090 times ]
Author:  ccherrett [ Sat Aug 04, 2012 1:23 pm ]
Post subject:  Re: Problems Calibrating
Another thought is this, I have a room that is 15 x20 feet with a six camera setup. The cameras are against the walls. Is this room too small for this setup?
Author:  Greenlaw [ Sat Aug 04, 2012 2:11 pm ]
Post subject:  Re: Problems Calibrating
Just a quick observation--the cameras seem a bit high up. It's good to have one or two cameras up high (8 to 9 ft) but the rest should be between 4 -6 ft up.

I used to shoot with PS3 Eye cameras in a space about that size but I used a half circle config because with a full circle the capture space got a bit too cramped for me. When I use PS3 Eye again it will be in our backyard where I have a lot more space. (I currently use twin Kinect in the living room for most of our motion capture sessions.)

G.
Author:  ccherrett [ Sat Aug 04, 2012 4:03 pm ]
Post subject:  Re: Problems Calibrating
Most of the cameras are 4-6 feet high. What that screenshot is, is the miscalculated results from running auto alignment on the cameras.

I just got a calibration with 4 cameras calibrated right, I am currently trying to manually calibrate the the 5 and 6 camera.

Manual calibration is proving to be difficult. Does it matter if the 5th and 6th camera are a touch out?

Thanks!
Author:  Greenlaw [ Sat Aug 04, 2012 7:42 pm ]
Post subject:  Re: Problems Calibrating
Okay, I see. That's pretty strange then.

Were the cameras arranged in iPi Recorder in sequence? I'm not sure this is necessary anymore but it probably doesn't hurt. Was the Maglite visible to all cameras when creating the calibration video? It's not necessary for the light to be visible to all cameras all the time, it is certainly preferable. Was clean background video recorded? I know all these questions may sound obvious but with so little info to go on, I want to eliminate the basic possibilities.

BTW, I would try to get the automated calibration working better. Attempting calibration manually is dubious at best and not especially recommended by iPi.

G.
Author:  vmaslov [ Sat Aug 04, 2012 7:44 pm ]
Post subject:  Re: Problems Calibrating
If you have good initial approximations of camera positions, you can go with "auto detect initial camera positions" disabled.
Author:  ccherrett [ Sat Aug 04, 2012 8:22 pm ]
Post subject:  Re: Problems Calibrating
vmaslov wrote:
If you have good initial approximations of camera positions, you can go with "auto detect initial camera positions" disabled.


I tried to calibrate them by measurements and turn off "auto detect initial camera positions" but the calibration still tried to align them and they moved all over the place.

At this point I am not sure what else to do, but I do have 3 feet on each side of the room I can move the cameras back, so I think I will give that a try.
Author:  ccherrett [ Sat Aug 04, 2012 8:38 pm ]
Post subject:  Re: Problems Calibrating
Greenlaw wrote:
Okay, I see. That's pretty strange then.

Were the cameras arranged in iPi Recorder in sequence? I'm not sure this is necessary anymore but it probably doesn't hurt. Was the Maglite visible to all cameras when creating the calibration video? It's not necessary for the light to be visible to all cameras all the time, it is certainly preferable. Was clean background video recorded? I know all these questions may sound obvious but with so little info to go on, I want to eliminate the basic possibilities.

BTW, I would try to get the automated calibration working better. Attempting calibration manually is dubious at best and not especially recommended by iPi.

G.


- I ordered the cameras in sequence and then also reversed that sequence
- I made sure the maglight was visible in almost all cameras at all times just to be 100% sure.
- I recorded about 5 seconds of clean background footage and then stepped onto the scene. I then set the desired ...... hmmm I have an idea, I am reading here in the wiki that I can set the approximate positions of the misaligned cameras and re calibrate. Going to try that.
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