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Experiences of using OptiTrack

Posted: Sat Jan 19, 2008 3:47 am
by gueedz
Hi I've been looking into applying for a bit equipment grant to buy an optical motion capture system. But now seeing optitrack I could probably afford it on departmental budget without a grant, which would be great. but before diving in and buying I'd like to get a feel for what (if anything) I would loose by choosing a low cost system like optitrack over a high end system such as Vicon.

Are there any Optitrack users in the london area or generally in the UK I could talk to about their system. Or anyone else who would like to share their experiences.

I've done a bit of my own research into the camera specs. I assume that Optitrack is cheap because it uses commodity cameras. The resolution of the cameras seems to be the same as Vicon, but the frame rate is lower. My interpretation of this is that the spatial resolution of the capture isn't going to be that different (maybe even better as I would be able to afford more cameras), but that optitrack might have a problem with faster motion. Is this consistent with people's experience?

BTW sorry to focus on the negative in this post, the system does look very good, and from looking at the videos the software looks excellent and much easier to use than Vicon


Re: Experiences of using OptiTrack

Posted: Sat Jan 19, 2008 4:44 pm
by Jim

I can answer a few of your questions, and hopefully the user community will jump in too.

We make our own cameras and they are based on similar CMOS imagers that are in other motion capture cameras. The V100 cameras are purpose built for mocap.

The V100 camera runs at 100 FPS, but has a shutter speed of over 1000 FPS (1ms), so we can stop fast motion without any trouble. We have actually done tests with golf clubs, as that is about the fastest thing we could think of, and we can stop the club head with no trouble. The issue is that you won't have that many samples of data with very fast motion. I can go into more detail if you like.

For spatial resolution, we are VGA, the same as lower cost Vicon cameras, and yes, you can add more cameras and increase the overall marker resolution.

Overall, we focus on smaller capture volumes, up to 20' square (although our users are now doing bigger volumes than we have at the home office!) We also only support one actor at a time now, but that will change shortly.

Our software is easy to use, but you will lose some of the really advanced skeletal setups and multi actor offline processing that other systems have. Again, we will be working on not only keeping our software simple, but powerful. Software upgrades are free for 1 year and $500 for renewal.

We have heard of customers buying our system for quick setup and pre-vis, but then they find that they really like the data and order more cameras and use it for production.

I hope users post here with their comments, but we have found that many customers are more secretive about their projects and don't post publicly. We do have systems in the UK, but again, it is not up to us to post who they are. Wish we could! :)

As always, we have a 30 day trial, and you can try it out. I would say that our customer care is excellent and if you would like to discuss your project on the phone or via email, we are here to do that.

Re: Experiences of using OptiTrack

Posted: Sat Jan 19, 2008 7:48 pm
by seanboyette

My Experience/Story with Natural Point...
I and a few others work at a large business firm often dream about animation, film and FX. We have alwasys wanted to start a small garage FX company in the Tampabay area - to meet our need for creativity. We have been doing research for sometime on potential motion capture systems and were also considering taking out a loan/grant to support our hobby/passion. We looked at mechanical, optical and post mocap sytems - all ranging from 20k to as you probably know, well over 500k. Then I stumbled on Naturalpoint. I as well as my collegues were very sceptical when we placed our order, how can a small company from Oregon provide us with an optical mocap system for 5k? One of my collegues told me that I was simply wasting my money! Then the package arrived, we quickly set it up and in less than 2 hours we had a suit on and were capturing data!! That same fried, said that there was no way it was working, and drove over an hour to see it for himself that night.

I have been using the system for sometime, and have tried just about every motion - from swinging of swords to tennis rackets and all are captured very well.
I must say, I love the attention and personal care that I get from a small company, and the community is steadily growing.
For my small studio its a perfect fit, should you need any additional info - pictures, actual examples - do not hesitate to let me know.


Re: Experiences of using OptiTrack

Posted: Fri Jan 25, 2008 12:13 pm
by gueedz
Thanks a lot for the feedback.

I have to say the forums are a big seller, there seem to be a very active community around the optitrack system


Re: Experiences of using OptiTrack

Posted: Sat Jan 26, 2008 8:06 am
by tvining
I've been watching the progress of Optitrack for years now (I recently ran across an email I sent to NP back in 2006), and it looks very promising--in fact my toes are right on the edge of the pool, but I feel like a need a nudge to jump in. The samples I've seen--like the tennis and boxing captures--are very impressive, but I would actually be using mocap for a lot of more mundane simple movements--sitting and talking, standing and bending over to look at something, etc., but I really haven't seen much of this type of thing. Sean, do you have any samples like this you'd be willing to show?

Also, as a general question, 6 cameras is considered minimum--with 8 recommended (and 12 even better)--but is anybody having success with 6?



Re: Experiences of using OptiTrack

Posted: Sat Jan 26, 2008 2:22 pm
by bsteagal

I have a 6 camera setup and been pretty successful with what I'm doing with it (mostly simple run of the mill motions, daily movements type of stuff) Although I will admit I'll be getting 2 more cameras once my income tax refund gets to me..

The biggest problem with only having 6 cameras is that you will have more problems with occlusions than with larger setups. I do a lot of cleanup of my takes that others probably don't.. I also have more problems because of my size (6'2") so I have to get it just right to give me the largest capture volume and balance between capturing my feet and my head at the same time.. My cameras are set about 9 feet high and in a roughly 20 x 15 space.

Here's a sample of some of the stuff I'm doing with it... this was for my children's church class.

If you have any questions, please feel free to contact me and I can give you more samples....

Re: Experiences of using OptiTrack

Posted: Sun Jan 27, 2008 2:00 pm
by Jim

There is a somewhat recent sample of more subtile data from a trade show we just did, check it out under the I/ITSEC section: ... html#arena

Really, we don't put up subtile motions because we can handle them with little trouble, we focus mainly on showing harder things, like push-ups and hugging.

For GDC (game developers conference) we will be releasing even more new features, hopefully enough for you to take the plunge! :)

Re: Experiences of using OptiTrack

Posted: Mon Jan 28, 2008 2:11 am
by hpcv
[quote=tvining]Also, as a general question, 6 cameras is considered minimum--with 8 recommended (and 12 even better)--but is anybody having success with 6?[/quote]
Keep in mind that the V100 cameras have a view angle of only 45 degrees. That is giving me trouble since I am working in a relatively small space. If you can place the cameras far enough away from your scene, you'll be fine.
[quote=gueedz]I have to say the forums are a big seller, there seem to be a very active community around the optitrack system[/quote]
The NaturalPoint people themselves are very active on the forums as well, always quick to respond and very helpful. (Great job guys, keep it up! :grin:)

Re: Experiences of using OptiTrack

Posted: Mon Jan 28, 2008 7:46 am
by bsteagal
Here's another sample of something I'm working on... captured with 6 cameras

Totally raw data, as you can see there are some small things that need to be adjusted (one hand flops over) and I have to adjust the animation to the character (for example, when he cups his ear, I have to raise the hand) but all in all it works really well and the animation I have to add is minimal.


Re: Experiences of using OptiTrack

Posted: Mon Jan 28, 2008 8:06 pm
by tvining
Thanks! But I have to say that Bryan's animations were probably the most exciting samples (to me) I've seen. Maybe it's me, but I wasn't that concerned that the system could track markers on the move, I was worried that the system would be jittery on markers that are standing still--I've seen a LOT of jumpy bvh files that make a "still" figure look like they're having a seizure, but Bryan's stuff looks very stable. Very impressive! I'm also impressed with how involved you and the NaturalPoint staff are in these forums, it's a big selling point. Okay...I need to take a few breaths....;-)