- [Instructor] The viewer wipe controls are
a very important image comparison
and analysis tool.
It also has built-in operations that provide
several methods of comparison.
So here are the viewer wipe controls,
but if yours are missing
it might be because you have your viewer
just a little bit too small.
See, they disappeared.
So I'm going to pull this open
to make sure they show up.
Also going to pull a little harder.
I'm missing my RGB guys over here,
so I'm going to pull that open until they pop in.
There we go.
Okay, we're good to go.
So the viewer wipe controls up here
you enable by hitting this pop-up here
and setting it to wipe.
Now it'll start with a wipe under
because that's the default for comparing
two different images.
So here's the set-up.
Here is Read 1,
which is this ocean,
which we see here.
Over here is Read 2.
I can toggle my viewer back and forth like so.
Now what you need to do is
you come over here
and under each input,
the A and the B inputs,
you'll see every single node that the viewer
is connected to.
It could be five or six.
I just have the two in this case.
So I want Read 1,
which is my ocean,
to be under Read 2.
So I'll select Read 1 here,
cruise over here,
pop up and select Read 2
and there we go.
Now the viewer wipe controls,
you can pan left and right.
You can rotate it
so that you can wipe
between any two images
in any direction that you want.
You also have this little fader bar here.
And you can pull the whole thing
off to the side
and do a complete fade
over the entire screen.
Okay, we'll put that back.
The next item is the over.
We're going to circle back to that in a minute
when we have a CGI element to work with.
The next wipe option is the minus.
Now this means we are doing
Read 1 minus Read 2.
So we're doing the ocean minus the clouds.
If I want to reverse that
then I would come over here
and say I want Read 2 minus Read 1.
And you can see
that's a very different result right there.
The other option is an onion skin look.
Okay, so let's go back to under.
So now let's take a look at how to do a CGI element.
First thing I'm going to do is
I'm going to turn off my viewer wipe control
by selecting the little dash guy here.
I'm going to hook up over here to my jet fighter
and punch up Input 1.
So now I'm looking at my CG element
and this is why I wanted my RGB pop-up.
I'll show you the alpha channel, okay.
So this is a four-channel, three-multiplied image
which you need to have
if you want to do the over.
Okay, back to the RGB.
So we'll select our wipe
and set it to over,
and I want Read 3 over Read 2,
and there we go.
So you get this immediate slap comp
or you can do your wipe thing,
you can do your fader thing.
And if I want to switch to the background like that
I can do that, no problem.
Now it spotted that I changed to Read 1.
If I had connected several things like this, okay,
I could now go over here
and say I want to see it over Read 2.
Now I want to see it over Read 1.
Ah, there we go.
Now we've been looking at the wipe option.
The stack option has the same exact operations,
over, under, minus, and onion skin.
The only difference is when you say stack
you don't get the wipe controls.
Now it can be kind of confusing in the set-up.
So I have written things for you here
in the backdrop node of this Nuke script.
So these are the various set-ups
and when you would use them and how.
The viewer wipe controls are also used
for viewing 3D wire frame objects
over their 2D image counterparts.
We'll learn about that later
during the 3D section of this course.