Now that we have successfully keyed out the green screen, let's add an interesting background
to take advantage of the alpha channel.
To do this, click on the Red Solid.
Then in the Effects and Presets type in "cell".
Drag Cell Pattern on top of the Red Solid.
In the Effects window, click the stopwatch on each of the attributes to set a keyframe.
Drag your playhead to the end of the composition.
Now let's change some of the attributes.
We can change to plates.
We can add more dispersion.
We can change the size.
We can change the evolution.
Now we have an animation behind our figure.
Again in Effects and Presets, type in Colorama.
Drag the Colorama effect onto the Red Solid.
In the Output Cycle, click the stopwatch to set a keyframe.
Then drag your playhead to the end of the composition.
Now select another palette.
I'm going to select Deep Ocean.
Now After Effects is keyframing to color palette behind our figure.
To make our figure integrate more into the background, we can use a technique called
a light wrap.
To make a light wrap, select the Garbage Screen layer and duplicate it twice by pressing Command
- D. On the second Garbage Screen, set its Track Matte to the Alph Inverted matte of
Garbage Screen.
Then select the top Garbage Screen.
In Effects and Presets, type choker.
Drag the Simple Choker onto the top Garbage Screen.
Solo out lower layer so we can see.
Notice that now we have an inverted matte of only the transparency layers.
If we add choke to the matte it goes inside the figure but it still has this harsh edge.
To get rid of that harsh edge, we can drag a Gaussian Blur on to the top Garbage Screen.
Blur out the edge and now we can precompose these two Garbage Screens.
Select them both, right click and then precompose.
Label this Light Wrap.
Unsolo the layer.
Now duplicate the Red Solid layer by pressing Command - D. Drag the Red Solid layer above
Garbage Screen.
Then set its Track Matte to the the alpha channel of Light Wrap.
As you can see it is now adding those colors to the edge of the figure but it is way too
powerful.
So to fix this, we change the blending mode to Color Dodge.
It is still a bit too powerful so what we will do it press T and lower the opacity.
Maybe something like 25 percent because this is a very bright scene.
Now if we zoom in, and we toggle the light wrap layer on and off, we can see how the
skin tone and the sweater start to seem like they are glowing from behind from the background.
This is a great technique to blend your different layers together.
Let's do it with a more traditional subject matter.
Here I have an ocean scene.
I'm going to drag it on top of the Red Solid layer.
And now notice that the light from this layer is coming from this side.
I need to have the light match the light of the figure.
To do this, I will invert the layer.
Go to Transform > Flip Horizontal.
Now the light is coming from the same side as the figure.
Press Command - D and duplicate ocean.
Also, press Command - D and duplicate light wrap.
Now, I will drag the ocean composition up above the other light wrap.
I will change its Track Matte to alpha matte light wrap.
Change its mode to Color Dodge.
Then press T for opacity.
And lower the opacity down.
If I toggle this layer on and off you can see that it integrates the figure much more
into the background.
There are many more techniques that I will show you in future videos to color correct
your keyed footage with your backgrounds.