Dual Kinect v2 for accuracy?


#1

Can anyone confirm whether having and using 2 kinect v2s set opposite each other helps Ni Mate capture mocap better. Especially for body turns and character bending/kneeling. As is, It appears to capture the turn about 80% well but when looking at the motiondata curves, I realise it doesn’t distinguish between a character facing front and back thus more cleanup than necessary.

I also read that dual kinect v2 can’t both work on a single PC…,coz of bandwidth issues. yet others say they do work. Can they or can’t they work on a single pc? Mine is a hpz840, intel xeonE5 2680v3 2.5ghz, 32gb ram.


#2

Two Kinects can be used at the same time, but each of them will output its own, individual data. The sensors do not interact in any way. This is as the analysis algorithm does not account for multiple sensors - it’s performed independently for each sensor’s depth feed. Multiple sensors can be used, for example, by pointing them in different directions to capture more people, though. Do note, though, that the infrared sensors cause interference to each other if they are pointed in the same direction as the infrared grid they project will be mixed with the grid of other sensors.

Multiple Kinects have immense USB bandwidth requirements. You will probably need an PCI-e USB3 extension card for the second Kinect.


#3

ok. thanks for clarifying this.
is thee a PCIe card brand you can recommend. or better yet, what transfer speeds/bandwidth or specs should I be looking for?
Also what suggestions might you have for capturing a body turn…or generally preventing the algorithm from freaking out when tracked points overlap…as in the case of a body turn, character kneeling, bending etc.
I’d appreciate your thoughts, links to read or tutorials. thanks.


#4

If I recall correctly, we’ve used PCIe USB3.0 extension cards with the Renesas upd720200 chipsets successfully (ie. this). We also had a Dodocool card, but for some reason it didn’t work, possibly due to software issues.

I’m afraid the loss of tracking on turning sideways is something that’s a limitation in the technology itself. A single camera tracking has problems detecting that border as the tracking algorithm isn’t smart enough to know if the person’s front or back is facing the camera. For actions like kneeling you might be able to get the tracking to work by making sure the sensor has optimal conditions. These include having no external IR sources (sunlight, other sensors) and the sensor seeing the person’s body in full, legs included.


#5

I bought this cheap card from ebay and it has worked fine for me. I think I am using the default drivers windows installs instead of the disc that comes with it.