The video was done quite quickly, since then I also upgraded the straps ( which were wobbling a bit at the time ) and also did some minor adjustmnent to the Json file which takes care of the calibration pose of the Mannequin, in order to tweak a bit the position of some joints ( shoulders especially and head ).
From reading the docs the calibration is based on the tracker being in a predefined area when the calibration starts, meaning that the body is divided into different parts corresponding to each tracker location, and from there I guess that they take the world position/rotation, attached them to the IK onto the entire body, and drive the animation like that, but also doing a bit of smoothing during frames, because I haven’t notice any twitching or weird things during the recording.
In the video you can see that one of the shoulders pops in place, but that was due to one of the Lighthouse being not placed efficiently.
I’m using 8 Trackers in total and I’m also developing a project where the user will wear 7 trackers and the HMD, and they also supply a setup where you can test the 7 Trackers+HMD setup, and it’s very fun to play with!
Overall I’m quite satisfied with the results, but the fact that you have to pay 200£ to have a custom character in UE4 you can drive with realtime animation still infuriates me, because it should really be a part of the deal, otherwise the streaming to UE4 is almost useless.