I think in history I've only successfully recorded 2 people at once only one time and back then I only had 1 laptop and barely had 8 PS3 cams working. In a couple of weeks, I'll be at a dance school trying to record again after 2 years of learning ipi and gathering gear, and I'm confident this time the recording will work better. Has anyone recorded a pair of actors? A better question would be have you recorded a pair of actors using Kinect v1 or V2? PS3 cams is my plan but if you've recorded with them before you know environmental conditions, clothing, and space (which I will have plenty of) are variables

I've done it. You can see some of the results here:
Virtual Reality dancing
(Two dancers at the same time is towards the start of the video).

I recorded with 6 PS Eyes, and a whole lot of colored clothing different from each other.
It also helped to have different colored gloves. I had to use kitchen cleaning gloves, not much variety in gloves besides white and red. You sweat a lot in those, I'd recommend putting small holes in them for ventilation.

I ran into a lot of issues in the hips area during turns. It's almost as if the dancers were moving hips first, then legs & arms. There was a lot of cleaning up.

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In my experience 6 PS Eyes are not enough to accurately have enough constantly seen data to track dual performer recordings, most likely why you state you had so many issues and a lot of clean up.

As with any optical tracking system, (maybe iPi devs can validate if this is accurate with this system), but I believe there has to be triangulation of at least 3 cameras to always have a body part in view and this is virtually impossible with only 6 cameras and dual performers, especially if positioned at a commonly set semi-level view plane.

One main thing that should always be kept in consideration is the center floor mark and all cameras should point toward it at a chest high level, and look similar in all the recorders view ports, set as horizontally level as possible, and I believe this will attribute to better tracking results, although I do this by default, it is just something to be aware of. (Willy-Nilly camera views in the view ports could not help matters anyway).

I have not tried this personally with iPi yet, (although I do know a direct overhead camera will function correctly, as shown in the rock climbing tracking forum post and videos), and commonly in other optical systems there is at least 1, (usually more cameras), positioned high above the capture volume looking primarily down, if more used they are set at slight angles, but always pointing at the same central floor mark.

This positioning should always give the triangulation needed and better results for close proximity tracking, although any hidden part, say a tucked in arm, or arms under the legs holding someone may still cause tracking issues.

I don't have the ceiling height to place a directly overhead camera, and I use only 6 PS Eyes anyway, but I do have 2 positioned at 8 ft. and closer in to the center floor point, which has helped in hip tracking and foot angle placement on the floor for the most part, and also for full body floor contact.

I would expect a minimum of 8-9 cameras to better accurately track dual performers motions, especially if in close proximity for longer periods like holding to the body, hugs and the like and using a particular camera positioning scheme for better triangulation.

I don't even worry with dual actor tracking with iPi much with 6 cameras, but I have done some bar seating and dance motions that weren't in very close proximity using my camera positioning and it worked out ok without too many major errors, attributed to the 2 high side cameras able to look over the head of the performers closer to it and specific positioning of the performers in the scene helped.

Older Vicon systems I have had experience with worked the same way when using a smaller number of cameras, and also how I learned using overhead cameras helps, I just haven't been able to attempt it yet with iPi in an area that would give the proper head clearance for that camera, which is a min. of 12 ft., but optimally would be 16 ft. to allow for raised arm extension, without blocking out the cameras view too much, as the closer a body part gets to a camera, the larger that object appears in the lens view, so with dances this spacing becomes even more critical when directly under the camera(s).

This is why I personally think it is better to have more than 1 overhead camera and place them a bit lower (12 ft.) and a bit further apart (3 ft.) pointing at a slight angle to the center floor mark, and I would prefer those cameras if only 2, to be used as side view cameras, but if only using one, I would suspect directly overhead would work best at a higher height, but still using the 2-8 ft. high side cameras also. (most users would want to use the minimum amount of cameras needed as each one added will add to the processing time in tracking and I haven't really seen any posts of anyone that uses 16 cameras during tracking yet anyway, 10 should be plenty for 2-3 actor recording, using this style camera positioning).

One day I am fully going to test this set up with iPi in an adequate location, (maybe someone can do it before I can though), but I do believe iPi is like any other other optical system, it just tracks color instead of luminescent IR balls, which does give more viewable area for the tracking at pretty good accuracy once all filters are applied, but you can only expect so much at 60 fps with a low resolution camera directly out of the program without some clean up, but that is required with even high end optical systems, even if real-time tracking with less cameras, with iPi at a considerably lower cost for set up, as iPi was only developed as a Pro-sumer software, and does a pretty good job overall, for me anyway using only 6 PS Eyes.

I hope any of this is helpful to anyone attempting similar recording, and maybe iPi devs can shed a little more light into the mix that may help, or explain how triangulation is a factor with their system.

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Shooting In a couple of hours from now.
Thought I would be notified when posts happened. Sorry I didn't see this stuff sooner.

As is, I plan to shoot with 8-10 PS3 cameras.
The space is big enough. It's literally a dancing school so the floor is clear of all obstructions except for an observation couch far away against the wall.

There are no fixtures in this room for attaching anything above the dancers, so while id love to do this, it's just not possible for today's shoot. Not even sure if how that's done was explained in any comments, but I know it was mentioned. I would love this of course but off hand i think I'm gonna need to let it go and hope for the best with a matrix-radius of PS3 cams.

I have 8 light stands
8 gooseneck clamps
2 tripods. Only one with an adjustable neck for added height.

2 pairs of Mocap gloves thanks to Snapz showing me the way (thank you!!)
One is black. One WAS white before I fat sharpied the color to be black...er. I think I feared contrast to the world but to each other may be just enough contrast to allow tracking to be okay enough.

2 GoPro head sets with motion trackers attached.

All motion trackers have been disassembled to their bare bones parts. Again, Snapz taught me this. It's too long for me to explain now but let's just say the result works, is way more compact, and great!

The dancers I think I gave instructions to not wear anything baggy or dressy. Woman had platform shoes on and I feared she may wear those today so I asked for something flat which I hope she does.
I tried to convey contrast, but I'm sure I didn't tell them specifically what to wear as far as color. I think with 8-10 cameras, ipisoft is going to figure out enough of what to record. I can't dress these people up. I'll bring a couple of contrast shirts in case this is a serious problem.

Need to get back to setting up my gear, making sure everything is charged.
Wish me luck!

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Good luck!

I would like to see how the shiny wood floor and the uncovered wall mirrors work in the tracking process, hopefully if it all works well you will post a processing video and final export video in the forum.

I saw the studio pictures and it doesn't have enough ceiling height for a direct overhead camera(s) anyway, but you could place 2 clipped to the ceiling at highest height possible, this works much better for foot tracking.

Clothing is a big deal with PS Eyes, and flat sole shoes or sock feet work best, although the program will refit to high heels also, if a solid color shoe.

I hope the dancers work with you as far as the best specs needed for good tracking, this helps the most for them to understand the process.

This being your first attempt at this will be interesting and you will learn a lot from the experience I am sure.

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I attached a photo of the space. Plenty of light and room to move around. Clothes I'll have to see how we do.

I will share what I can here:)

I'm wondering about ipisoft studio.
I have license codes yet to activate.
For what I'm shooting today, will I be able to process the recording in a trial version of studio?
It's been a long while since I tried multiple actors and back then my company paid for a pro package. Prematurely in retrospect. I didn't have enough gear to do what I wanted. Today, I have a 3 month pro package license but wasn't planning to activate it until later this year.

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You would be running on an expired trial version, not sure how many cameras that supports though, so you can process the videos, you just won't be able to export the animations out and you will be processing in "Locked" format, so be aware you will have to re-track any videos you do with the trial again to be able to export them once you activate your license.

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I filmed in a similar dance studio environment. If you can, try to cover up those mirrors, at least during calibration.

On my setup, I put the PSEyes to darken, keep the lights on (they are sort of fluorescent tubes, so more area lights instead of point light sources like yours), and block ambient light coming from a window. The problem is that you have your calibration lamp, calibration tracking will have issues trying to figure out which is the brightest light source from the reflections (especially if the calibration lamp is blocked out of sight but the reflection isn't). I also put dark tape on top of every light source, even the PSEyes power indicator. If possible I would keep those head lights to a minimum.

Mirrors are troublesome during calibration, but not so much during tracking, even though there are actors reflection. Mirrors also helps the dancers get their bearings. I tape some markers on the floor to aid the dancers to know where the center is, and what are their boundaries. Waltz is problematic because it moves so much that the actors go off camera constantly. Be sure to activate one mic per recording computer used to record if choreographing to music. It'll make posing of the fingers with respect to music much easier later.

I used the Basic License to track each person separately. It has its limitations of course. First of all, it tracks separately so it takes twice as long for two actors. Also if I understand correctly, each actor has collision boundaries, so if I used the Pro version there would be less issues of the actors melding into each other (we do closed partner dancing like tango) and a lot less cleanup on my part.

Good luck and let us know how it goes!

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I understand your time at the studio is limited, but...

I also can see those mirrors if not covered during calibration could cause issues, but the iPi tracker does do a good job of separating foreground from background reflections, or objects during the performance video tracking.

I also personally would unscrew all direct lights over the capture area and tape white paper over all others, and still have plenty enough light and you can adjust lighting later inside iPi Studio by other means just as easy through the monitors graphics card settings.

Very bright lighting seen by the PS Eyes will turn into very bad results on the video once inside iPi Studio and can easily affect your tracking results.

Also remember to do post session calibration, always good to have a second calibration file just in case!

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+1 to post session calibration. Don't skip it!