Using iPi DMC with Dual Kinect Sensors [dKS]

Greenlaw · **Posted:** Thu Oct 13, 2011 11:11 pm

Now that the dual Kinect Sensors [dKS] feature has been released for beta testing, I thought it would be a good time to start a thread for users to share their experiences and results. I'll go first:

First a little background: I'm currently making a very short (1 minute) film for an art festival, and I designed the film around using a single Kinect with iPi DMC. I need to reshoot a couple of motions so the timing for this release couldn't be more perfect.

I've been using a six year old duo core laptop with the single Kinect with success so I decided to give it a try with dKS. Unfortunately it turns out that even though this laptop has six USB ports, it may actually only have one USB controller. I would have sworn that it had two controllers (required for dKS) but it doesn't appear that way when I examined what was going on in Device Manager. If I swap the USB cables around, I can get either Kinect to work but only one at a time. Eventually, I connected the second Kinect to the USB 3.0 Expresscard that also has the USB 3.0 drive I was using to store the Kinect data connected. I didn't expect this setup to work either...and it didn't. Both Kinects were working correctly now but when I tried to record, there wasn't enough bandwidth for the hard drive. Oh, well.

On to plan B...

Luckily my desktop computer is just outside the living room. Using two USB repeater cables, I was able to extend USB connections an extra 16 ft and now I am getting a very strong signal from the two Kinects with absolutely no dropped frames. This computer has an SSD dedicated to capturing motion data from six PS3 Eye cameras so I'm not expecting any difficulties with capturing from two Kinects.

The problem now is that I cannot monitor what's being captured because the computer is in another room. I would ask my wife to help but she's already gone to bed. Sigh!

Maybe the cats will assist?

Oh, I know. This computer has a small 'laptop' Cintiq attached which has a cable that may be just long enough to position the screen past the doorway. Yes, our house is starting to look like a crazy mad scientist lab. I better get this portion of the project wrapped up before morning. :p

G.

Greenlaw · **Posted:** Thu Oct 13, 2011 11:13 pm

Yes! The Cintiq reaches the living room and I can use the Wacom Stylus to control iPi Recorder.

Stay tuned...

Greenlaw · **Posted:** Fri Oct 14, 2011 12:25 am

Using the Cintiq to control iPi Recorder seems to work well. I have the device propped on the floor in the doorway so I can monitor what each Kinect Sensor sees and position them precisely. Tilt is controlled by a built-in motor and I can operate the motor for each Kinect through the Cintiq. Using the Wacom stylus I can align cameras with reasonable accuracy this way. Totally unnecessary but gotta admit this is pretty cool!

One drawback. When I double-click a video panel, this should fill the screen with the live video to help with ‘across-the-room’ visibility. However, when I double-click a video panel on the Cintiq, the video expands on my main computer monitor which is in another room. Oops. Can’t use that feature I guess. No biggie.

The cats are intrigued. I have some fun ‘captures’ of Sergeant examining one of the Kinects up close.

One of the nice things about using a single Kinect was that it didn’t require calbration. Not so with dKS. However, dKS calibration is still much easier than calibration for the PS3 Eye configuration. It basically involves holding up a flat board (I’m using a sheet of foam core) to the Kinect Sensors and slowly moving it around. After tracking this data in iPi Studio, the scene data can be saved and reused for all motion tracking data shot for that session.

Note: need to get Kinect tripods. Toullie just jumped on the small table where one Kinect sits, which messed up my calibration. I put in an order for two of these:

CTA Digital Xbox360 Kinect Adjustable Tripod Stand

This stand looks more stable than other models I’ve found online. It’s also more adjustable and it has a built-in level. FYI, I found an interesting Makerbot template for printing a plastic tripod mounting head but I don’t have time for that right now. Cool idea though. I will have to try it out later.

Final note: The cats are definitely a problem when shooting mocap data; they’re just too curious about the process and they refuse to stay ‘off stage’. May have to lock them in the kitchen when I’m ready to shoot tonight.

Bandwidth test is good. Ready to shoot calibration again.

G.

Greenlaw · **Posted:** Fri Oct 14, 2011 12:30 am

Decided to call it a night for dKS. I have tomorrow off so I can continue in the morning after I drop off child at school.

G.

kristi_12 · **Joined:** Mon Aug 01, 2011 6:24 pm **Posts:** 19

Thank you Greenlaw for all your contributions.

Pat · **Posted:** Fri Oct 14, 2011 10:28 am

Okay, so I have a stupid question. How does one go about updating to this new version of IPI? Is it just a matter of downloading the new recorder?

Thanks.

Pat

mrbones · **Posted:** Fri Oct 14, 2011 10:46 am

Hi Greenlaw, I found Calibration easy.

Set up both your cameras kind of high at level proportions.

Heres how it goes... Just step to middle of room with white board and hold at a rectangular angle at your camera 1.

Then make sure there are less yellow dots, the less yellow dots the better.

Then set a take for 500 frames and hit the calibration button.

Once thats done save it. That saves both the cameras room angles..

Then you can recall that scene for each subsequent tracking session.

More later

Greenlaw · **Posted:** Fri Oct 14, 2011 12:08 pm

Pat wrote:

Okay, so I have a stupid question. How does one go about updating to this new version of IPI? Is it just a matter of downloading the new recorder?

If your computer is connected to the internet, the software should auto-update (you'll get a message when you launch the software and a chance to cancel updating if you decide against it.)

If this doesn't happen then either: 1.) your software is already up-to-date, (check the version number,) or 2.) something is blocking the update (firewall maybe?)

Alternatively, you can update it manually by downloading the latest software directly (assuming the one on the website is current, and it usually is.)

I think you need to update the Kinect drivers manually...this isn't completely clear from the QuickStart Guide...but it probably doesn't hurt to update them to the latest version anyway. x32 and x64 drivers are on the QuickStart page. In my case, I didn't have to un-install the old drivers to make this work.

Hope this helps.

G.

Greenlaw · **Posted:** Fri Oct 14, 2011 12:14 pm

mrbones wrote:

Hi Greenlaw, I found Calibration easy.

Same here...I just held up a foam core board and rotated is slowly. Being able to see the Cintiq behind one of the Kinect Sensors helped me control the angle of rotation. I probably recorded way more data than I needed but I *think* my calibration is good. I'm not 100% sure what I'm looking at yet. FWIW, I only see green dots...no yellow dots anywhere. I think the ground plane might *possibly* be off but I need to do some actual mocap tracking first to be sure. :p

Calibration seems a lot slower than with PS3 Eye but in tracking a 3D plane instead of a single point of light, I think the software is trying to do something more sophisticated. More later as I figure out what I'm doing.

G.

Greenlaw · **Posted:** Fri Oct 14, 2011 12:31 pm

Some info and tips:

I recorded my session this morning with the RGB stream enabled. This is a pretty cool feature. As Andrew mentioned, this option gives you a full color video to use as a reference video. This stream is optional as it isn't necessary for tracking but it can be useful if you have trouble understanding what's going on in the depth video.

If you have bandwidth issues when recording, you can switch this feature off to improve the recording speed. If your footage contains the RGB stream, you can choose to hide it or show it in Studio by clicking the appropriate button.

If you play the video with a standard player (Media Player Classic for example,) the video will display as multiple panels of video channels. This is normal. If you want to output the color video file, you'll need to load it into Studio and output a new video file with the desired camera view and display options selected.

G.

Using iPi DMC with Dual Kinect Sensors [dKS]

Who is online