Original subtitles

[Autogenerated] welcome to Module three channel operations in channel

operations were going to be going into using the channel merge and

understanding how the different operations allowed is to move data around

within your composite and to work on channels by themselves.

We're going to focus on this one node.

The channel merge.

When do you use it?

A channel merge is the same as a merge.

Except the merge is for RGB and A and other channels.

Whereas a channel merge is much more detailed.

It just allows you to merge and do Boolean math as

well as combining just the channels.

So when we think about channels, think about red, green, blue Alfa.

It just allows us to merge and manipulate those channels by themselves.

In this clip,

we're going to take a look at the channel mergers interface and how it works.

And then we're going to go into channel merge operations.

Look at how each one of the different operations interacts with the channels

with our knowledge base of the merge operations and the channel merge were

going Teoh implement them and construct our own version of a light rap that

will allow us to wrap colored pixels from the background onto our foreground

imagery to create compelling work.

So let's take a look at the channel.

Merge now!

Now the channel merge can be gotten from right over here in the channel.

Drop down right here.

This node right here, Channel merge!

Now the thing about the channel merges that you can see that we have in a input.

We have a B input.

There is a mask over here to the right.

And then there's the output.

Now all the nodes have some really interesting things

that are right there in front of us.

The channel merge Not only has the name of the node right here,

but it's actually telling you what it's actually doing by default that

Shamel merge is set up to do math on the Alfa Channel.

It is doing Alfa U stands for Union Alfa equals Alfa.

So the first one here is the A input a The Alfa of A will be union with

the Alfa of B and that will equal the output Alfa.

And you can see right here that there's only a white tick mark

at the bottom signifying that this node Onley processes Alfa

Now let's open the properties.

You can see here that the properties has the same kind of layout

we have are a channel which is rgb dot alfa.

We have our B channel, which is also Alfa,

and we have our output, which is Alfa.

And right here in the center is the operation.

And you can see how I said before that it shows you use for union.

Let me switch this to something like a minus and now you

can see that it gives us the minus sign.

If I switch it toe Plus you can see we have a plus symbol.

Let's go back to union for right now as that is the default and we'll

hook it up to this science star and a yellow circle.

And let's bring up our control panel again.

So right now what's happening is it is taking the Alfa of the A,

which is our star.

It is taking the Alfa of the circle and it is out putting in Alfa Now We

don't see anything over here because we're displaying RGB.

Let's go into our Alfa Channel and we can see now that it is a

combination of the A and the B those two together are now resulting

in this it is putting them together in tow.

One new channel, Let's go back to RGB A.

So let's take a different channel here and let's take,

say,

the green out of the A and put it into the green of the output and

you can see that that shuffles in a different way.

But this is a channel march,

so in effect you can achieve some level of shuffling inside the channel march,

and it's not really often Lee used this way.

Most usually we are, generally speaking,

were using it to process Alfa, as is it.

And that is why that it defaults to Alfa.

Let's close this up now.

I want you to understand that it is now merging these two you can see we have

RGB and a RGB and a and down here has now it's out putting rgb and a but notice

that the shapes of these channel boxes have changed.

This one is full size just like it is here.

But these ones are smaller Nukus telling you that it is

simply passing through the RGB data and this node the channel

march is not doing anything to it.

It is just allowing it to pass through.

Where is the larger Alfa Swatch is indicating that the Alfa has changed.

It has been combined, and that's why if we go over to the viewer in a,

we can see that it is changed.

It is a combination.

So we're going to go to the next clip,

where we're gonna learn about all the different types of math that we can

apply to the different operations of the channel merge.