FreeTrack Forum

Cam: Lorex IR DCM 2161

Reflective tape: brand new (had these laying around unopened) Jogger's Ankle reflectors

Frame: homebuilt from coat hanger

Getting 30fps just testing without the reflectors.

Now a few questions.

Will 1/2 to 3/4 circle reflectors be sufficient?

Should I make a frame in the three reflector config or 4 with one up high and 2 or 3 low?

Cam will go to 640X480, will I have to use it with the reflector setup?

Drafin

And how about this as an easy solution for not having to build the reflector frame?

http://www.naturalpoint.com/trackir/02-products/0-resources-products/TrackClip-black-isoRight.jpg

I currently design IR tracking glasses for another (WiiRemote IR based) tracking project. This also uses retroreflective markers and I wonder, if its 3 markers in a single (vertical) plane are equivalent to your 3 marker solution ?

If some of you are interested in replacing the Basecap with wires with a lightweight plastics glasses frame, please tell me the best fitting marker distances.

The current design is a triangle (base marker pair = 116 mm apart / 30mm above eye level, top marker is 40mm above base pair (70mm above eye level).
All markers use 3M scothlite (R) self adhesive tape disks of 12mm diameter.
As far as I know, FT can be configured to any marker geometry - but what is best for 3-point tracking ?

My plan is to put the design online as open hardware project so you may give it to a local laser cutting service - or order the pre cut kit from me or others from the community who want to serve as kit providers.

Did anyone think about replacing the current webcam with CPU demanding image processing by the WiiRemote that handles all processing/2D-tracking and only sends the XY-coordinates of 4 marker center points ?

The main reason for the tracking glasses project will be headtracking for a pseudo depth (2.5D) linux desktop with the option of true stereoscopic (Stereo3D) viewing on normal LCD screens  

As far as I know, FT can be configured to any marker geometry - but what is best for 3-point tracking ?

The three points can't be in a plane parallel to the webcam plane because then the z depth of the model is close to zero and the orientation becomes uncertain with 4 possible solutions. This a fundamental limitation of using planar point models for optical motion tracking. The most stable configuration is when the model plane is perpendicular to the camera plane, like the 3 point clip.

To apply this to sunglasses would require extensions for the side leds or middle led to create some visible depth in the model.

Did anyone think about replacing the current webcam with CPU demanding image processing by the WiiRemote that handles all processing/2D-tracking and only sends the XY-coordinates of 4 marker center points ?

I've implemented it, it works well, but I have to sort out issues with the FT interface standard for 3rd party apps before it can go wild.

Hi Kestrel,

Why do you put the Wiimote at your cap/head ? Our Project comes with a DIY LCD-mount for the Wiimote including IR-LEDs near its optical axis to reduce the headgear to 3 retroreflective markers.

Because the wiimote is the camera and not on your head,  you would need to aim the wiimote at yourself and use  reflective tape,  ( the obvious advantages are, no led's no batteries, and 100 fps with nearly 0 computer usage)  I was going to build an led setup, now I am going to wait for the wiimote update.