Fast moving marker disappearing from scene

[panda]

I have a 10x Flex13 setup in a relatively small capture area (2m x 2.5m). I'm using Motive 2.3.

I did some captures the other day with one character and props, but I noticed that when the character was moving relatively fast, the props weren't being properly tracked.

I took a closer look and found that for the frames where the character was moving fast, the markers themselves had disappeared from the scene. I did another test capture just with a couple of rigid objects, and I noticed the same thing. When the markers are moving fast, they simply disappear from the scene. Motive detected 11 markers when the objects are at rest, but it goes even down to 4 when they are moving fast. This was a test with all other factors removed, so there were no oclussions or issues with the markers going outside the capture area.

Here's the test capture where you can see this happening. On the slow swings, all the markers are properly tracked, but when they are fast, they disappear from the scene.

https://www.dropbox.com/scl/fi/daq1lt86 ... zmll0&dl=0

I tried setting an exposure faster than the default of 500us. I even went down to 100us, but there were no noticeable changes.

The OptiTrack FAQ says that it can track swinging golf clubs at more than 200 km/h with 360Hz cameras. Mine are only 120Hz, and the movement is a bit fast, but not unreasonably so.

What should I do to properly track fast moving markers in my scene?

[Erinvenus68]

Thanks for sharing this—I'm running a similar setup (Flex13s + small volume) and experiencing something comparable when tracking fast-moving props. Have you tried adjusting the threshold or gain settings in Motive to see if the system is simply not registering the motion-blurred markers as reflections? Also, have you checked if IR LED power on the cameras is sufficient for your setup size?