Someone bumped into Kinect during long recording session :(

Tammo · **Joined:** Sat Mar 03, 2012 6:25 am **Posts:** 2

During a day long recording session with an actor someone bumped into one of the Kinects.
Nobody noticed it.
It looks like it is a few degrees off for most of the takes.

Since i am new to this i only made one calibration at the beginning.
I should have done it before every take.

Do i have to record everything again or is there a way to still track this?
Can one of the Kinects be disabled?
During video import i can't change the number of Kinects to use.
Would one Kinect with good calibration be better then two with one bad calibration?

Here are the images of camera2 before and after the accident:

Greenlaw · **Posted:** Sat Mar 03, 2012 10:18 am

Ugh...what bad luck.

IMO, it shouldn't be necessary to record a calibration video for every motion--to me, that seems like a waste of time.

Of course, if you have a frequent problem with people bumping into the equipment, that a very serious problem. I would make it repeatedly clear to the crew that they need to be careful on set and to report 'bumps' immediately so a new calibration video can be shot. Another tip: mark the areas around your cameras with brightly colored tape to keep up awareness. You might want to tape down the cables too, just to be safe. (FYI, even when I'm shooting alone, I keep a roll of brightly colored tape on hand--it's useful for marking tripod locations of cameras, lights, where the performer needs to stand stand for T-Pose, and the boundaries of the capture space.)

Just to be sure, you may want to shoot a calibration video both before and after the entire session, or shoot a new calibration video after a long break (like lunch or dinner.)

Obviously, it's important to keep a record of which calibration videos are associated with which motions. Each time you press the spacebar to start and stop a capture, iPi Recorder saves the video with the timestamp in it's name, so what I like to do is copy the file name after recording it into a spreadsheet with a brief description of the video (i.e., 'calibration vid', 's03 - s07 Sergeant walk', etc.) This reference is extremely useful when putting the scenes together later in my 3D program.

As for salvaging the 'botched' footage, would it be easier to just reshoot the session? For me, setting up the Kinects and recording takes only a few minutes, which can be a lot faster than trying to force 'bad' footage to work for you. The entire capture session for our short film 'Happy Box', for example, included motions for three characters for 17 shots and we (me and my wife) were done in about an hour with rehearsals.

G.

Tammo · **Joined:** Sat Mar 03, 2012 6:25 am **Posts:** 2

Thanks for your workflow tips,
i will do that at the next recording session.

The problem with reshooting is that i hired an actress who was able to do some sport moves,
like skiing, ice skating and something with wheels like inline skates but for winter sports.

So before hiring her again i will try to get something out of the material i already have.

I started tracking and so far the results are better than i thought they would be with the wrong calibration.

Adjusting all the body morph sliders to fit her shape seemed to have improved the results.

Its really amazing to see how far apart the two point clouds are and that IPI is still getting a result.

Another mistake was that there are some glass windows in the shot.
They seem to introduce some additional noise.

Greenlaw · **Posted:** Sat Mar 03, 2012 3:56 pm

Glad you're getting some of the footage to work.

Tammo wrote:

Another mistake was that there are some glass windows in the shot.
They seem to introduce some additional noise.

Yes, with Kinect, reflective surfaces can mess things up--it's probably bouncing the IR rays and misleading the software. Black surfaces can also cause errors. A little bit is fine but a lot can be problematic.

The PS3 Eye setup can also have problems with reflective surfaces, though for different reasons.

G.

InfoCentral · **Posted:** Sun Mar 11, 2012 10:35 am

Greenlaw I now have 1 xbox kinect and 4 ps3 cameras. I am deciding which way to go, to add 2 more ps3 cameras or 1 more kinect. In your experience which set-up produces the best finished output?

Greenlaw · **Posted:** Sun Mar 11, 2012 12:24 pm

I think it depends on what you need to capture and how much space you have. If you need a very large capture space, PS3 Eye is still the way to go. (Kinect max space is 7 x 7 sq ft; PS3 Eye is 20 x 20 sq ft.)

That said, I really only use the twin Kinect setup these days, and I keep the PS3 Eye setup as a backup for special situations. The reason is that most of the motions I need can be easily captured in a smaller space and the Kinect system is more convenient--you can set it up quickly and the results are pretty decent.

If you're asking which system is more accurate, I still think it's the PS3 Eye. It's because, even with only four Eye cameras, you have more coverage than with 2 Kinects. Even though you can place two Kinects opposite each other for 360, you're still getting that coverage from only two vantage points. With four to six PS3 Eye cameras, you can not only encircle the subject completely, you can stagger the heights to increase visual coverage further. Of course, setup is more complicated. But then again, you may get fewer tracking errors.

Sigh! I guess that's not exactly answering your question. :P

Okay, if I had to choose between the two choices, I'd get another Kinect. It's just a whole lot easier to setup and use and the results are quite good. But that's just me. If you need to capture the type of motions Jean Dellac or 1k0 is capturing (i.e., lots of running and jumping,) I think you need the six camera PS3 Eye system.

Greenlaw · **Posted:** Sun Mar 11, 2012 12:31 pm

Another consideration is hardware: I think (but I'm not completely sure,) that two Kinects will work with a less powerful computer than you need for six PS3 Eye cameras. Be advised that I have never actually compared for this, it's just an assumption.

Maybe iPi Soft or another user can confirm?

G.

InfoCentral · **Posted:** Tue Mar 13, 2012 2:27 pm

Great, I think I will try to borrow someones Kinect and try the dual out first. The Kinect for Windows is now quite expensive. Getting the 2 additional PS3 cameras would be cheaper at this point. I am still remodeling the studio and hopefully will be ready to start testing by the end of the month. Thanks...

Greenlaw · **Posted:** Tue Mar 13, 2012 2:59 pm

At the moment there doesn't seem to be any advantage to using Kinect for Windows with iPi DMC over Kinect for XBox, other than that it's 'officially supported in Windows' by Microsoft. My understanding is that the extra cost is mainly for the developers kit that comes with it.

That said, things may change in the future.

G.

Someone bumped into Kinect during long recording session :(

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