forums.naturalpoint.com

Does SDK have a way to record time-lapse images? I'm a track IR user at home (awesome!), but am currently studying the growth rate of spines on Saguaro cacti. I just need a way to track movement on the order of 0.1 mm every five minutes over the course of a week. I briefly considered using my TrackIR to do this, but can't find a way to get the image onto my Mac.

I see in the other posts that the Optitrack can be placed up to 3 cm away from an object. I figure if I just put a piece of reflective tape on the tip of the spine, a visible light filter in front of it (Is this the non-IR filter lense?), I might be good to go. No?

Would focus be a problem?

Does SDK include a scale feature (i.e. I can specify what distance a certain # of pixels equals?)? I just need to know the rate at which the marker tape moves (variable) over the time period measured.

Thanks for your time and great products!

Cool project, the OptiTrack SDK and camera might work for you :

The OptiTrack SDK does not have explicit support for time-lapse, but it could certainly be used to accomplish that by having your application capture frames from it at the desired interval. The SDK will only report position data in two formats, the first is the 2D x,y position of the detected markers on the imager and the second is the 6DOF position when tracking a vector clip (which would be too large in your case). You could calibrate the 2D position data by showing it an object of known size and calculating a conversion factor between pixels and physical distance. The camera would need to be about 4 to 8 cm away to resolve movements on the scale of 0.1 mm using the X axis of the imager.

There are a couple of differences between a TrackIR camera and an OptiTrack camera which are relevant to your scenario. TrackIR cameras lack adjustable exposure, LED brightness control and a lens which can have its focus changed. This would probably prevent the TrackIR from working at a close range since the image will be out of focus and too brightly lit. The short distance would be pushing the limits of the OptiTrack camera's lens, but I believe our testing has shown that it would be able to resolve (small) markers at this distance.