All language subtitles for 02. One Point Tracking

In this lesson, we're going to be learning how to do a simple, one-point track.

OK,

so I'm just starting off here in your Project Files in

your NUKE Files folder in the 02_begin.

NK script.

And if you want to, you could just open up NUKE and just use a blank NUKE script,

because this is basically what this is.

I'm just starting from scratch here.

OK, so also go ahead and have those project files open.

And let's go into your Reference Files folder.

And I've got that opened up right over here.

And we're going to be using this one-point zombie track.

So go ahead and just grab that folder, click and drag it down,

and just drop it onto your Node graph.

We'll move this out of the way.

And then let's go ahead and hook up our Viewer node to our Read node.

OK, so I'm going to go ahead and hit Play.

And we'll just watch this play through.

And we'll talk about what we want to do here.

So I want to create a track that's going to track

the motion of our zombie's head,

because I have a little piece of text that I want to

follow along with his head as he's moving.

So basically,

the tracking in NUKE 7 has changed quite a bit since earlier versions.

But it is also a lot more easy to customize now.

Now for a basic track,

you not really going to need to have a lot of

different things going on with that.

But I'm going to show you just an easy way to set this up,

just to achieve this simple thing.

So now that we have all of the frames cached here,

I just want to take a look at what we have going on with his head.

So let's talk about what you need to look for whenever you're

trying to get a good track in a piece of footage.

So one of the first things is you want to do is something we've already done,

which is play through the sequence before placing your tracking anchor.

So we'll talk about what the tracking anchor is in a second.

But we've already gone ahead and played through this,

so we kind of have a feel for the track.

We have a feel for what's going to happen, what this motion looks like.

Now second think you want to do is to look for features that are

consistent throughout the majority of your clip.

So we're starting here on frame one.

And I kind of scrub through.

And the things that are most consistent about his head here are maybe his ear,

this big kind of sore on his head, on our zombie's head.

All of those things would definitely be good things to track.

Now what are some of the things you want to stay away from?

You definitely want to avoid areas that are heavily shadowed or

heavily lighted that the lighting changes on.

So right away, maybe one the first things you might think is,

oh, well, we could track this area on his neck,

or maybe this area on his cheek.

But those areas are going to change over time, because of the lighting.

So you don't want to track things that are based on the light.

You want to track features that are going to stay the same.

Now you're not always going to be able to have something

that stays exactly the same over time.

And we're going to talk about that in some later lessons.

But for this, I just want you to get the basic feel of this.

Now the main thing you want to look out for whenever you're

finding an area to track is contrast.

So I think that this area right here, it's a great contrast.

We've got this light area where that skull is kind of showing through.

And then we have this area around it that's much darker.

So let's go ahead and add a Tracker node and get started.

So I'm going to move back to my first frame.

And you don't always have to start on your first frame.

But for this track, we'll go ahead and just start here.

It's going to be just a little bit easier to work with.

OK, so to add our Tracker node,

we're just going to come over here to our Transform button.

Just click and hold that down.

And the tracker is going to be just kind of out of your view.

It's about three down from underneath this area here.

So another way you can get to it, if you don't want to drop it in that way,

is to simply hit the Tab key and type in "Tracker.

" There you go.

Now we have our tracker.

Let's go ahead and hook this up.

So I could either just hook this up like that,

or just drop this on to the pipe where my viewer is.

So I'll just go ahead and do it that way.

And you notice nothing changes right away.

But we do get our tracker popped over here in our Properties Bin.

So this version allows us to add as many tracks as we want.

We don't have to choose just a certain kind of track we're going to be doing.

But for this track, we only need one.

So you're just going to come down here to your Add

Track button and click that one time.

And you can see that it just adds a tracker for us.

And we also get these other two options here.

Now these are going to be-- or these other two viewers,

these are going to be really helpful,

once we start doing some of the more complicated tracking.

And even in this lesson,

we're going to have to do a little bit of just things

it's going to need to use these viewers.

So I wouldn't close those out.

Just go ahead and leave those up.

So we want to move our tracker first.

And you need to know how the tracker works,

before you just start grabbing things.

You want to move it from this middle cross-hair here.

And this area right here is called the Pattern Area.

So this is what you want to move to place on top of the

feature that you're going to track.

If you don't grab it right here in the middle,

you try to grab it on the side, you're going to start resizing it.

Now in a little bit, we will want to resize it.

But for now, we just want to move it.

So just click and drag this over.

We're going to try to get this over onto that area on his forehead.

Now I'm just going to middle-click on my mouse wheel and drag,

to move over here to this area on his head.

So let's go ahead and get that framed up a little bit better.

So now that we have that right on the center of this feature.

And I'm going to go ahead and make this a little bit smaller.

Now this area is the search area.

The search area is going to be where NUKE looks for

this pattern as it moves across time.

Now you may first think, well, gosh, how big does this area need to be?

Because if it needs to track this over time,

then maybe it needs to be as big as the area that the feature will move.

Now that is not true.

It only needs to be as big as the area that the pattern

will move from one frame to the next.

So that's a great reason to watch this over time,

so you can kind of get an idea of how big those

increments are that your feature moves.

So this is only moving, maybe, 20 pixels at a time, or so.

It doesn't look like it's having too many extreme movements.

Now right about here, it does pick up some speed.

So we may run into some trouble there in that latter part of our track.

But let's just go ahead and go back to our first frame.

And I think this is a pretty good size for the search area, actually.

It's OK to have it a little bit bigger.

You don't want to have it too large, or it can mess up your track.

And also, it's going to take longer for NUKE to be able to calculate that.

So what you want to do when you want to start your track is make sure

your track is selected over here in your Tracker Panel.

And then you're going to come up here to this area right there.

And these are going to be the controls you use to do the tracking,

forward, backward.

So there's a few different things that we'll look at here.

So this button right here is going to just simply track to the next frame,

the one with the little line before that Play button.

This one is going to track all the way to the end.

So basically what NUKE will do with this button is it's

going to track until it runs into a problem.

So this is a pretty automatic way of tracking, by clicking this button.

So it's just going to try to do it on its own.

Sometimes, it's too fast to see if there's going to be mistakes.

So a lot of times, if I know I'm going to have a difficult track,

I'll work with this simply Track Next, and just go to the next frame.

But for us, this is going to be fairly easy.

Let's just start out with our Track to End.

So I'm going to go ahead and click that.

And you can see that this area doesn't move right here.

We only see this area moving.

And then, if you noticed whenever we were back in this area,

basically, our video moves around on the outside of this box.

And it simply centers in on the feature.

So that's really helpful.

This box, I use all the time.

So let's go ahead and zoom in a little bit further here

and see what went wrong with our track.

Because you notice, at the end of that, we weren't on our zombie anymore.

This went somewhere else completely.

So something went wrong.

So let's go ahead.

Now right here, I'm looking at this area.

And I'm just watching to see where those cross hairs

are in relation to the feature.

And I don't even really have to have this area in view,

but I'll go ahead and pull it up here just so you can see.

Now whenever I'm doing tracking and I'm checking from frame to frame to

see if the tracker is on the right point in time,

I like to use my Arrow key.

So I'm going to hit the Right Arrow key to move forward from me.

See that moved me forward to frame two.

And you see it moved the track forward one point.

So let's just go ahead and move through here.

I'm just watching over here in this area to make sure that that stays in place.

Now it looks like it may have gotten off just a little bit.

It's not quite in the center.

So if you want to, you can just click in the middle and move that into place.

And that will adjust the tracking data for you.

Let's go ahead and keep moving forward with our Arrow key.

I'm just going to hit that Right Arrow again.

And you see that it moved kind of back over to where we were before.

So this could be a problem,

if you move something and you don't start tracking

again with that new piece of data.

So actually,

let's hit the Left Arrow key to go back to where we adjusted this track.

And then what we need to do is delete all of the tracking

data that comes after this eighth frame where we know

everything proceeding that was correct.

We know we got off track somewhere in this area.

So what I want to do is delete all this data.

So to do that, I want to delete everything forward of frame eight.

I'm just going to come up here to this little button right here.

And that's going to clear forward.

It's going to clear the animation from that point,

wherever that current time is.

So go ahead and click that.

And you can see it cleared out those frames.

Now sometimes it leaves a few behind.

And it doesn't really matter.

Once you start tracking in, those will be overwritten.

So you don't really need to worry about that.

Just make sure you get most of them gone.

It's going to make this look a lot cleaner.

So now we don't have a squiggly track line that

doesn't really make any sense to us.

So let's go ahead and finish this track out.

I'm going to go ahead and, this time, let's just click the Track Next button.

So I'm going to click that.

See now that looks much better.

That's staying in place, so let's just click this a few more times.

And this is really more of a key frame tracking style.

And I really prefer to track in this way whenever I'm doing

something that maybe has a lot of motion blur,

or not as much contrast as I want,

because automatic tracks almost always have some kind of an issue.

Now definitely, adjusting your search and pattern areas is going to help.

But sometimes,

you're just going to have to get in there and do a

little bit of the hard work yourself.

Now it looks like the track got off a little bit.

Even though I was clicking it by hand, I was talking to you.

So it looks like I just kind of have gone backwards here to about frame 27.

It still looks like it's in the right place.

Let's scrub forward to frame 28.

And here,

it looks like it starts to lose a little bit of its area

that it's supposed to be searching for,

because it gets very blurred from this motion blur.

So sometimes, you can adjust this pattern area and it's going to help.

But sometimes, you just have to do it by hand.

So I'm just going to go ahead and move this back over here.

Let's track forward one frame.

And then we'll move this into place.

And let's just get through this area here that has

the intense motion blur by hand.

So I'm going to middle-click my mouse wheel and pull this

over here and just put this in place.

Now if there's a not enough contrast, or if you're zoomed in too close here,

looking over here is very helpful.

You'll be able to just figure out a little bit better where you are.

And you notice, as I pull this around, this one is moving as well.

So sometimes I'll be moving it here in this window,

and then I'll be looking over here to see exactly where I need to place it.

OK, let's go ahead and track forward another frame.

Move this over here.

And again, just checking forward to the next frame,

and then repositioning that anchor.

And sometimes you're going to get a track that's perfect.

Sometimes you're going to be able to automatically track

all the way through your entire sequence.

It really depends.

A lot of times, live action footage that has motion blur,

though, is going to give you some problems.

Now you'll notice I've clicked that Track Next a couple of times.

And it's really staying where it needs to be.

So once I kind of get through a problem area,

I'll switch back over to that Automatic Tracking and track to the end.

So let's go ahead and click that.

And just watching that through,

it looked like that really stuck on there very well.

So I'm going to watch this window here and scrub backwards,

just to make sure that it is staying on that region.

And that looks great.

OK, so we have basically created a track.

We've finished tracking that through.

We hit a few problem areas, but we learned how to work through those,

simply readjusting the tracker and using that Track Next

whenever you're in a difficult spot and you can't just

track all the way to the end.

You're also going to learn later on that you can track backwards.

You don't have to just use that track forward.

But for this lesson, it was just a little bit easier to do it that way.

OK, so now what do we do with this data?

Well, as I said earlier,

we have a little piece of text that I want to track

along with our zombie's head movement.

So we're going learn how to apply that data to another piece of

footage or another still image in our next lesson.

So stick around, and I'm going to show you what to do with this tracker data.