All language subtitles for Nuke Compositing for 3D Artists week 2 - Classroom - CG Master Academy_2

so the tracker note

it's pretty straightforward um

it has one input

and that input would be the image you want to track

so in this case

we will plug in our landscape image into our tracker

and if I pop this properties out

we could see it a little bit more easily easily

um so by default

it starts with this tracker tab and um

it's pretty straightforward

where we have the option of adding a track

deleting tracks

selecting multiple tracks and also averaging tracks

and what we wanna do is start by adding um

a track so that we could start um

figuring out the motion of this footage

so to begin with

we're going to select at tracks

and you can see this tracker 1 was just generated

and what the tracker likes is areas of high contrast

and it does a pretty good job from there

calculating where that point

that pixel is going in the

uh frames ahead

so um in this case

we could start out by maybe doing a point um

we could start

out by doing maybe a point right around here

or maybe over here um

just it's got a good contrast against this bright sky

so what we'll do is we will drag our tracker

and we will set this right here

and as you can see

we've got this magnified zoom

zoomed in view of where our tracking

um bounding boxes

so what we're seeing is this region right here

and so we could also use this to kind of line up

but generally

we'll just use this to line this up um

this inside box is the um

image the area around the point you wanna track

so if we had a tracking marker

you would essentially just scale this in

so that our tracking marker fits directly inside that

and this outside box

you would use to expand if you're working with

the footage that has a lot of motion in it

and the images really pans in and out

and there's heavy motion blur

you would expand this box

so nuke knows that that pixel might

shift drastically within frames

but in this case

since it's a pretty linear motion

we're just gonna leave this about here

and once we've got our points selected and lined up um

your tracking controls are all up here in the viewer

so you have the option of

using this forward arrow to track forward

or you could do this tracking forward using

a frame range dialogue box

so if you select this

you will get

this forward tracking dialogue box

so you basically select

from what frame to start tracking to

and to what frame to stop at

so in this case

we wanna do the full sequence

which is 100 frame

so from here

we would just hit okay

and you could see

our images tracking pretty nicely

and sticking to that point we've set

and if I pan over and we could start scrubbing

you could see that point

is doing a good job sticking to

to where it was

so that's great

that looks like we've got

ourselves a pretty good track right there

um and there's no limits to how many tracks

you could add in here

so if we wanted to track another point on this image

um we would simply just select add tracks

um in this case we'll do another track

but this time we could track backwards

so I'll go to our last frame frame 100

and let's select

um maybe uh

another point on this on this um

on this image

and maybe we could do a point in the background here

so we'll do add track

and now you could see we've got another track

it's called track 2

and then we will we could line this up to say um

point back here

it's a good another high contrast area

so we could just

push in this inside box

and we could expand this outside box a little bit

and now we could use the track backwards dialogue box

which is this one right here with the R

and if you select this now

you could see we're going from frame 100 to frame 1

which is what we want since we wanna go backwards

so if I hit okay

you could see we're starting to solve

and that point is doing a pretty good job sticking

to it and you could see in this footage here

it's sticking

um sticking pretty well

great so now we got ourselves another good track

and that looks like it's sticking pretty well

and what we could do is

now we could add another track point

and I could show you um

what you would do in

the situation where that tracking point

might go out of frame

and where we need to switch to another track point

so to do that

what we could do um will

add a track

and in this case

what we'll do is maybe set this track to

say this point right there

and I will

I will get that nice and tight right there

and um in this case what I'm gonna do instead of

using the Track Forward dialog box

I'll just use the normal track forward

button right here

and halfway through it all stop this

and we could change points

just so we could demonstrate what

you would do in that case

so I'm gonna hit track right now

and I'm gonna hit escape and stop this on frame 50

now let's say this point had gone off frame

and we needed to track another point

but we still wanted to be part of this same track data

what you would do on a Mac

you would hold the command key

and I believe on a on Linux and PC it's control

but on a Mac it's command

so if I hold command and grab this point um oops

where's my tracking point

let me zoom in here

um if I hold command down

you see this yellow line that has been created now

um I could move this to another track point

so for example

we could go to this point right here

and if I hit track forward now

you'll see we'll be tracking

the nuke will be tracking this point

but it will still

keep the data on this track 3 curve right here

so if we hit track now

you could see it's tracking that point

but it kept everything on this same path here

so it essentially becomes a new offset point

so that's a handy way to deal with a point

that is no longer in frame

and you need to continue that same track point um

so that's great

so now we've got ourselves three

3 solid track data

and if you um

now that we're happy with this

we could get into um

how to use this track data to track another image

uh to this um

generally what you would do is

if you wanted to just use one point

you would just check this

checkbox right here

so this stands for transform

R is rotation

s is for scale

so if you were solving

for an image that has rotation in it

or the image pushes in or zooms out

you would use

you would wanna check the rotate and scale

um options as well

to calculate the scale change and the rotation um

both the rotation and scale um

they will not work

if you don't have more than one track points

normally the tracker needs at least

2 track points to know

and calculate the rotation and scale for it

so that's something to keep in mind

but in this case

if you just want to use Track 1

we'll make sure transform is selected here

and we're good to go from here

and then we could

we could get

get get the other datas for it