WEBVTT

00:00:00.000 --> 00:00:05.850 align:middle line:90%


00:00:05.850 --> 00:00:09.840 align:middle line:10%
So in the cases where
you've gone and done all

00:00:09.840 --> 00:00:13.590 align:middle line:10%
of the labelling that you can
and still you see that some

00:00:13.590 --> 00:00:19.740 align:middle line:10%
of the markers do not have 100%
of their trajectory filled,

00:00:19.740 --> 00:00:23.380 align:middle line:10%
then this means that there
are gaps in the trajectory.

00:00:23.380 --> 00:00:27.300 align:middle line:10%
So these are our points where
the markers were occluded

00:00:27.300 --> 00:00:32.000 align:middle line:10%
or they went outside the capture
space or something like this.

00:00:32.000 --> 00:00:35.590 align:middle line:84%
And so the next stage of
post-processing would be to go

00:00:35.590 --> 00:00:41.920 align:middle line:84%
and identify those gaps, which
in many cases will be visible

00:00:41.920 --> 00:00:43.270 align:middle line:90%
on the--

00:00:43.270 --> 00:00:48.610 align:middle line:84%
so in this editor by red marks
or sort of blacked-out parts

00:00:48.610 --> 00:00:49.903 align:middle line:90%
of the trajectory.

00:00:49.903 --> 00:00:54.240 align:middle line:90%


00:00:54.240 --> 00:00:54.740 align:middle line:90%
Yeah.

00:00:54.740 --> 00:00:58.390 align:middle line:84%
So that you have a couple of
choices for how to fill gaps,

00:00:58.390 --> 00:01:00.520 align:middle line:84%
you can either do
this in the software.

00:01:00.520 --> 00:01:03.400 align:middle line:10%
Most of these softwares
have some algorithms

00:01:03.400 --> 00:01:07.150 align:middle line:10%
that you could use to fill the
gaps where you'd choose to use

00:01:07.150 --> 00:01:09.700 align:middle line:10%
some sort of interpolation.

00:01:09.700 --> 00:01:12.040 align:middle line:84%
So you might choose to
use a linear interpolation

00:01:12.040 --> 00:01:13.810 align:middle line:90%
or a cubic interpolation.

00:01:13.810 --> 00:01:19.030 align:middle line:84%
This depends on the type of
movement that you're expecting

00:01:19.030 --> 00:01:25.360 align:middle line:84%
and also the length of the
gap, the duration of the gap.

00:01:25.360 --> 00:01:30.400 align:middle line:84%
And normally you don't
want to use an algorithm

00:01:30.400 --> 00:01:32.360 align:middle line:84%
to fill gaps that
are very large.

00:01:32.360 --> 00:01:36.430 align:middle line:10%
So I don't know what your
personal cutoff point is.

00:01:36.430 --> 00:01:42.820 align:middle line:10%
I kind of would often use around
50 milliseconds for most kinds

00:01:42.820 --> 00:01:43.660 align:middle line:10%
of body movement.

00:01:43.660 --> 00:01:47.360 align:middle line:84%
If it's something
where the movement is

00:01:47.360 --> 00:01:51.640 align:middle line:84%
elapsing very slowly, then
maybe I would use a larger--

00:01:51.640 --> 00:01:53.920 align:middle line:90%
a larger duration.

00:01:53.920 --> 00:01:57.430 align:middle line:84%
But you don't want to
automatically fill a two-second

00:01:57.430 --> 00:01:59.230 align:middle line:90%
gap because that's--

00:01:59.230 --> 00:02:02.260 align:middle line:84%
there's quite some things that
a person can do in two seconds

00:02:02.260 --> 00:02:07.110 align:middle line:84%
and just guessing what they
did is not very useful.

00:02:07.110 --> 00:02:10.280 align:middle line:84%
So you can do this
in the MoCap software

00:02:10.280 --> 00:02:12.560 align:middle line:84%
but you can also do
this after exporting

00:02:12.560 --> 00:02:17.240 align:middle line:84%
this data into whatever analysis
software you choose to use.

00:02:17.240 --> 00:02:20.450 align:middle line:84%
You can use some kind of
mathematical interpolation

00:02:20.450 --> 00:02:24.920 align:middle line:90%
to fill the gaps.

00:02:24.920 --> 00:02:27.140 align:middle line:84%
Another thing that you
can do in some cases

00:02:27.140 --> 00:02:32.540 align:middle line:84%
is use information from other
markers to fill one gap.

00:02:32.540 --> 00:02:34.940 align:middle line:84%
So I've done this
sometimes with markers

00:02:34.940 --> 00:02:37.520 align:middle line:90%
that are located on the torso.

00:02:37.520 --> 00:02:40.340 align:middle line:84%
So for instance, if you
have a chest marker here

00:02:40.340 --> 00:02:42.880 align:middle line:84%
and then you've got a couple
of markers on the back,

00:02:42.880 --> 00:02:45.840 align:middle line:84%
these tend to move
quite in parallel.

00:02:45.840 --> 00:02:49.290 align:middle line:84%
So if the gaps are
located in the chest,

00:02:49.290 --> 00:02:51.890 align:middle line:84%
you can use the information
from the back markers

00:02:51.890 --> 00:02:54.080 align:middle line:84%
to help you fill the
gap that's in the chest.

00:02:54.080 --> 00:02:57.430 align:middle line:90%
[MUSIC PLAYING]

00:02:57.430 --> 00:03:04.000 align:middle line:90%