external positional tracker for generic mobile headsets

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rbairos
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external positional tracker for generic mobile headsets

Post by rbairos »

Hi everyone.

I've recently been getting caught up in VR through work, but one thing I've noticed:

There seems to be several mobile VR apps, and even mobile VR headset adapters (homida, cardboard, samsung gear, etc) but they all lack positional tracking, and are limited by the phones rotational sensors.

Does this product exist, and/or is it a viable product idea:

1. A stand-alone base device consisting of a camera, processing logic and some transceiver (either wifi or bluetooth).

2. A set of LEDs (battery powered) that you can affix to some device (ie, the front of some generic mobile VR headset)

This would allow one to very cheaply use almost any phone (bluetooth and/or wifi enabled) to provide a fuller VR experience,
offloading the tracking to the base device, which relays the info back to the phone.
Phone would not even require accelerometer / gyro / etc.

Ideally it could track more than one set of LED markers, so you could affix some to your cardboard, others to a hand-held controller, etc.

Apologies in advance if I'm describing half a dozen existing product kits.

Rob.

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cadcoke5
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Re: external positional tracker for generic mobile headsets

Post by cadcoke5 »

There is a product by NaturalPoint called TrackIR. But, the processing is in the PC that runs the web cams. There is also a similar open source version called Free Track. I imagine there is some lag with the process, since a USB web cam introduces significant lag all by itself.

But, the big limitation would be software to get the phone to accept and used the position data.

-Joe

rbairos
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Re: external positional tracker for generic mobile headsets

Post by rbairos »

Thanks , I did come across TrackIR, but like you said it requires an entire PC to do the processing.
Free Track seems to be a good resource.

"I imagine there is some lag with the process, since a USB web cam introduces significant lag all by itself."

Ideally the processing would be stand-alone, in some dedicated embedded processor,
and the imaging device driven at a faster frame rate for the same reason.
I'm assuming it would not be difficult to process full frames at 120fps or higher in this context.
And bluetooth protocol hopefully less than 6ms.
So not prosumer grade tracking, but the whole premise would be a very cheap VR interface for existing mobile phone users, somewhere between cardboard and samsung vr gear.

"But, the big limitation would be software to get the phone to accept and used the position data."
Yes, I was envisioning it would employ some open standard that game developers employ directly.

Cheers
Rob

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cadcoke5
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Re: external positional tracker for generic mobile headsets

Post by cadcoke5 »

I forgot to mention the Wii controller set-up. Johnny Lee created a demo program to show its usage with a computer monitor. It already has a Bluetooth interface built in, and does some processing internally. However, the bluetooth is a version that does not have the security settings that Android now requires. The Wii controller can track up to 4 individual LEDs.

Another product is the CMU cam. This was designed for robotics usage, and it can track color "blobs". But, the resolution is fairly low.

I am puzzled that Samsung didn't build in some method of tracking in their Gear VR. All it really takes is an external camera with an internal processor, and a few LEDs. It is a technology that has been around a while. But, perhaps time lag for the processing has been a problem. That is why a camera with a built-in processor is a good idea. The processor can be a specialized DSP chip. But, all that is beyond my electronics ability to design.

-Joe

rbairos
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Re: external positional tracker for generic mobile headsets

Post by rbairos »

I recall the Johnny Lee setup when writing this post.
I don't know CMU. I'll look it up.
Yah, Im puzzled too, why no mobile headset manufacturer offers a tracking solution, inspiring me to write this post,
to gauge if it's an interesting or redundant effort.
Thanks for your input!
Rob.

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Re: external positional tracker for generic mobile headsets

Post by WiredEarp »

I thought TrackIR does processing internally as well, similar to Wiimote. My understanding was it simply returns x/y coordinates to the host pc, rather than a raw image that needs processing by the PC.

I could be wrong though, its been years since I read the specs on trackir.

I've used Freetrack as well, its surprisingly good with a decent webcam. I'd look there first before spending $100's on TrackIR, which in my country at least, is still > $250.

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cadcoke5
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Re: external positional tracker for generic mobile headsets

Post by cadcoke5 »

My memory on the TrackIR is also vague. I tried to see if I could find more info on the web page, but I did not. Note that the TrackIR's main purpose is as a mouse substitute. Though they have done a little with 3D position tracking. Of course, the biggest issue with these items is that you have to find software that is compatible. I inquired if there was any software that would use their product, that would permit me to view CAD drawings. But, there was none.

-Joe

rbairos
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Re: external positional tracker for generic mobile headsets

Post by rbairos »

Since posting, it seems there a few companies that do this.
A couple of which are:

http://vicovr.com/

http://sixense.com/wireless

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cadcoke5
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Re: external positional tracker for generic mobile headsets

Post by cadcoke5 »

I looked up those two items just now, and here is a bit more info.

http://vicovr.com/ To be shipping April 2016. I could not find a price. Their technology is comparable to the Kinect, but adds the internal processor that does the work. It is also wireless, sending the tracking info via Bluetooth. The latency is 30ms for the processing, and the wireless transmission adds 10ms.

http://sixense.com/wireless An absolute position tracker, with a range of 16ft radius from the coil. It tracks 5 sensor, each with 6 axes. $490 for the 3 sensor bundle, and $580 for the full 5 sensor bundle.

-Joe

rbairos
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Joined: Fri Oct 30, 2015 7:23 am

Re: external positional tracker for generic mobile headsets

Post by rbairos »

Thanks for the quick specs.
In summary: too slow or too expensive!

Im guessing the 30 ms latency may be a function of the frame rate of the vicovr camera? (~30fps) ?
I see sixense was had a kickstarter campaign from 2013.

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