forums.naturalpoint.com

Dears,

I want to build a software to reconstruction the humam movement in 3D space. This software will be used in biomechanics analysis. In the true, I already built the software and used common sony cameras (DCR-HC28) to track the movement on outdoor enviromments. The system works well using those camares. Now, I intend use my system on indoor enviroments and use infrared cameras. So, I am going buy of natural point the following products to use in my system:

- 4 v100 flex CAMERAS (4 x US$529)
- 4 tripod: Bogen Deluxe AutoPole2 Black with Bogen AutoPole Base Black and Bogen Super Clamp with 3-way Head (4 x US$210)

and the acessories:

- Raw material (count : 80 strips)
- USB Cable High Grade - 3ft (count: 2 cable)
- USB Cable High Grade - 15 ft (count: 4 cables)
- OptiTrack Sync Cable - 15 ft (count: 4 cables)
- USB 2.0 Active Extension Cable - 5m (count: 4 cables)
- USB 2.0 Hub (count: 2 unit)
- USB Cable : 15ft A to B (count: 4)
- Reflective Markers : Facial (count: 4 pack)
- Marker Base : 1.5" Soft Base, 8/32" Stud (count: 5)
- Marker Bases : 1" Hard Base Short (count: 2)
- Marker Bases : 1" Hard Base Tall (count: 2)

I wish that someone give me a advise if I forget somethink or if there is some important product that I must buy. Are the listed products sufficients/adequated ?

Thanks very much

Alan Petronio

Alan:

You are planning on using our free OptiTrack SDK to access the individual cameras raw data and feed those 2D points into your software? If so, then the 4 V100 cameras will work for you.

If you would like 3D data, and lens calibration, you would need our Rigid Body software, and potentially more cameras to get good 3D coverage of a full body (6 or more are recommended)

Also, in a future release of ARENA, we are adding support for a general purpose API that will give you the human joint angle data directly, similar to real time BVH data.

For the cables, you probably want 15' USB cables, not 3' ones and 4 of them. You only need 2 of the 15' A to B (one for each USB Hub). You might only need 1 hub as well, for only 4 cameras.

The Facial markers are very small, just so you know.

For the Marker Bases, they are just bases, no markers attached, I assume you are building your own markers with all that reflective material?

We can prepare a quote for you if you email into sales@naturalpoint.com

Questions and answer:

Q: "You are planning on using our free OptiTrack SDK to access the individual cameras raw data and feed those 2D points into your software? If so, then the 4 V100 cameras will work for you."

Ans.: Yes. I intend use 4 x V100 cameras and your free optitrack SDK. I will use de 2D markers coordinates (provided by the cameras) and use DLT to reconstruction the 3rd coodinate. Our system uses the Direct Linear Calibration algorithm to calibrate the cameras. So, we just need the 2d coordinates of the markers.


I have others important questions:

1)What algorithm are you using to camera calibration ?
2)Is there any article explaining your camera calibration algorithm ?
3)You try use the DLT in your system ?
4)Wich are the most important limitations of the V100 camera ?

thank you very much !!!!!!!!!!!!!!

Alan Petronio
UFU - Brazil