hi this is Russ Anderson this tutorial
I'm in a run through some
additional scenarios using offset
tracking
to show what you can do with this
capability this particular shot
has a bunch of occlusions do and I like
to the bars on the windows
but I said to the people walking by so
perhaps the one at some other plane onto
the tarmac out there
so we want to start out
we're just gonna generally doing some
to rise tracking and that's the whole
thing here surgeon at a tracker
onto this plane in the back
obviously we need to have a ride a
different trackers
to do this so
printers scanners zoom in on this guy
bear now ready to start tracking and do
the shot
Lindsay do that I'm just using the
middle mouse wheel here
and as he did I see that we to be do get
into some spots where
the for Nicole sizing needs to be
increased to bet
nor other things also let that but still
normally I would but they graph editor
on the bottom
know this camera Graffeo this particular
situation we've got no eliminate capture
window here just so that we can
be able to upload play this back for
everybody
so we're just gonna create our own that
I've year with day
graph editor on the side so they know we
are staying there
animate up the
the search sites
so I see the lucky that it's just a
nine position K so we'll just continue
using a mouse wheel turns into the shot
and here comes our side had going right
in front
so all you wanna do so is fine an
additional feature to track
wall are primary feature
is being occluded
by the foreground object now
the two things that we wanna do
this first off we wanna pick something
that's roughly at the same
distance and position in the image
as our primary teacher here the
other day criteria really is that we
wanna have both
the features visible right at the
beginning
and also right at the and have the
occlusion
so a spot that
meets those criteria
ABS this lettering on the side of the
plane there
so would use that
is our position to track while our
primary location is being included
so we return on a
offset channel indicate that we're gonna
start doing asset tracking
NEC we picked up a few extra
little markers there RC what's going on
a little bit more in a sack and
and here's the cute thing that I wanna
do
I'm gonna hold down the shift key and
then I'm a star dragging I can drag me
then the camera video
or and may many chakravyuh
and as I do that the sea then there
graph editor where and their
Control Panel were animating values for
the offset channels
that are being added to the tracker
location that's being tracked in such a
way that we get back
exactly to the location that we really
want to be tracking
so we've done two things
we've remove the tracker visible tracker
be like
to our new feature that we on a track
we're also created keys
on the offset track offset channels that
exactly take the final tracker location
back to our original Spock and having
done that
now we can start tracking to the shot
and sent ice continues to update
the location I had the visual feature
and
to that gets added the the offset
it set up now here are
original features reappeared
to read ready to turn the offset channel
back of
you don't need it anymore but before we
do that
wanna go over into the camera mio just
reposition that offset marker
back
to our original location the desired
location
we're gonna wanna be tracking and that's
an important step because it's updating
are offset channel key is it's creating
new offset channel keys
so that in the middle part in the shot
send eyes will be interpolating those
offset channels so did the final
location stays as accurately as possible
in there spot that we won
even know it you can't really be seen
because at the foreground object but the
idea is to be as
accurate as possible all throughout that
in a beating
interval said suggesting that by law
said I it was an important
part of that process and depending on
how much camera motion there as how much
perspective shift
the adjustment in a might be substantial
and
once we've done that now we can go
and turn off the offset
and you'll see that they're said that
has created new keys that brain
the pattern that were visually tracking
back to the location we want to track so
now we can continue on tracking at
and it says F
you know where we're not using the
offsets that are so describe back
do see can say even in the intervening
part
we still have that cross air sitting
there
in the right location known even though
the shots bouncing around a bit
and whatever and
one other thing to notice in a mill in
the offset part
the many tracker via here
is showing in the visible feature that
is being tracked but
if we go and locked the camp their
Lakhpat tracker market is done
now it does go and
it just stays in its always showing that
by a location
to the behavior of what you see in the
many tracker via ON
salmon track window for that matter
varies depending on whether the tracker
is locked or not
organ unlock it go had some more fun
with this tracker
so now here comes our second
person walking by and
if we scrubbed due this shot the same by
the end of their
Shah and the end that occluding portion
he's blocking a feature that we
had tracked and not first
a closure so it's not really gonna let
us do the same thing using this same
original location
so I no-show every turn a
offset track back on the same Ross
entire from before is being used and
that brains they
reference pattern down here and
they could hold down the shift key again
and move this guy around a little and
and tune that up
and that would be fine right up until
the end
to wear and where you that thing is
still going to be blocked in this
pattern is not going to be visible
so instead we are all dil
is just go and again ima hold the Shift
K
and let's just go to a different
location
so here's a different location that we
can track
that will still be visible
at the end of the occlusion to hear our
pattern
has reappeared over here this guy is
still visible
that we're tracking so now
began you are final adjustment the
position and this guy
and
then we'll turn the offset channel back
of
that hops back to our regional location
now we can keep on tracking
to the shop so now a
we've gotten through both those to
occlusions
using two different AlterNet
features to track while they feature
is being included an
as far as the sovereign's concern
dollars it's going to be looking at
is that final location that's nice since
moved
even while the people are walking by and
naturally Drabek especially when you
have
only a limited number features that are
trackable in the first place
especially with object tracking when
there may not be that many features so
this lets you keep
everything trackable even if things
Timberlake get occluded now place we
started tracking here in the middle of
the shot
all this stuff can be done in reverse as
well
on a show you what happens making gallon
just change the direction this tracker
and prepare for
tracking in reverse misusing the rate
collected
irate tractor just that space in their
someone to change the direction and the
tracker
and you watch over here any Grath
editor I track mio you'll see that there
are a bunch of additional keys that our
work
created and those are necessary to make
sure our
that everything remains the same
if your gonna go to the and and now
playing throw
you wanna still get the same results
track ending up in the other direction
that actually takes a bunch of
different hockey instead to make sure
that everything works in reverse
so now restraint seen their share
much among penis their slits just use up
that
third size again now we come up to
now they're spot where the pattern
becomes occluded
say let's just add
Dec one other feature for starters
manager are asset channel on
and it drops back to that previous
feature
and wellness shift dragged a little too
fine-tune their
now just to be interesting just a
realist racin
let's consider what happens
F life is really tough there isn't a
single feature available to track
throughout the time there her primary
features blocked
so I've been using this feature here but
suppose now this one gets blocked
and something else becomes visible that
I need to use instead
so I can do about that again I can just
hold down the shaft
I'm a drag up
to a different feature to track now that
makes life
a little more and resting let's go and
take a look
if les scrub backwards do this shot
those last couple frames
if you look at the by opposition here
you'll see that it's actually changing
around
the reason for that has to do with the
interpolation up the offset channel
between those two frames basically it's
always linearly interpolated
but because we've actually move the
pattern to a different location
normally that with the offset staying
the same that that makes they
final location change of South so what
we actually need
is a kindest aerCap
staircase up pattern
in me offset chat now so to get that
I wanna so lacked
the two keys
on the offset channels and when to hold
down
using that to move in time
button on the graph editor
I'm gonna hold down the Control K and
slide those keys in time to see if I go
all the way there
it's flattened out the art that's
completely that's one frame too far
actually want the frame just immediately
before that
so now I've created a flat section
in the offset channel so that
we get the right off thats
to keep the
final position and exactly the right
spot
there may be a little tricky their
understand
all I can say I think about it a little
arm
again the by a position as always
the position that's being tracked plus
the offset channels
so in this case when we're moving me
pattern that we're tracking
damn from one spot to another just on
one frame
that means we have to do something
similar and the offset channels
thats create a very steep switch there
as well
so I need to get that setup
and now I can continue tracking
back to the beginning at the shop
a point at the in need to do
deaths adjustment to the key is the
cloning and the key is
be poorer you do the tracking from this
point back to the beginning in the shot
eager is that that has to do
with the tracking Mona I've actually got
just a steady camera mode
so with that with the protection that
sent dies is still in here and that
steady my heart
it's expecting this position to be to be
stable
an until you fix up day
keys over there if you
are using that steady mode the
protection for where the pattern is is
gonna be grossly of
that by just been using you know one on
the handheld sticky nodes and the
handheld sticky note here
I wouldn't have that problem but with
the
when a steady motion is being expected
that's what you need to provide before
you go and do the tracking and the
additional portion at the shop so to
something
to watch out for just be sure to
picks up your %ah sexys as soon as you
make that
different move up the point2 tracking
I think in in jail this should really be
a very rare situation where you have to
actually switch to a different pattern
it in the middle %uh they occlusion if
you need to do it
you can go and and check this out may
need to think about a little
but you can go and between the map
editor
and the different modes any camera view
many chakravyuh you can get P what but a
little better thought
cell up with this is given you some
ideas as to what you can accomplish
with the asset tracking capabilities
so enjoy
