- [Instructor] In this movie, I'll introduce you to
the opacity mask.
And we'll ultimately use this feature to get the
stripes off the model's nose
and achieve this final effect right here.
Now I'm going to be demonstrating how an opacity mask works
on this photographic image.
And that's going to serve two purposes.
First, we'll see how opacity masks differ from
the clipping mask, that we saw back in chapter 23
of the advanced course.
And you'll also see how opacity masks most closely
resemble layer masks inside Photoshop.
Alright so I'm going to go ahead zoom out of this image here.
And I'll turn off the glasses layer.
And then I'll twirl open the image layer
and I'll select the clipping group.
Now we're going to remask this image.
So I'm going to release the current mask
by going up to the object menu, choosing Clipping Mask,
and choosing Release.
Then I'll go ahead and target this top path outline
in the image layer, the former clipping mask,
and I'll press the back space key or the delete key
on the Mac to get rid of it.
Alright let's zoom in a little bit here.
And I'm going to go ahead and select the Ellipse tool
from the Shape Tools flyout menu.
Then I'll position my cursor on the bridge of her nose
and I'll press the Alt key as I drag in order to draw the
shape from the center outward, until it's about a big.
Next, I'm going to increase my stroke.
Notice I've got a black stroke, but it's just
one point thick.
I'm going to crank it up to 20 points.
And I'm going to go ahead and set the field to white.
And then just to give you a real sense of what's going
on here, I'll go up to the Effect menu,
choose Blur, and choose Gaussian Blur,
and I'll go ahead and set the radius value to
five pixels and click okay.
And we end up with this blurry looking shape.
Now I could convert this to a clipping mask
just by selecting the contents of this layer,
which you can do by clicking on this little wedge
in the top right corner of the layer, here inside
the layers panel.
And then you can go to the object menu,
choose Clipping Mask, and choose Make.
In which case we end up losing all those attributes
as well as the Gaussian blur.
That's not the end of the world though.
I can reestablish the attributes
by twirling open this clipping group
and targeting the clipping mask, which is going to be
the top path in the group.
And then I could go back up here to the stroke option,
and set the line weight to 20 points,
and we get a big black line.
However if I go to the effect menu
choose Blur and choose Gaussian Blur,
and apply that same radius of five pixels, nothing happens.
And that's because clipping masks don't support
dynamic effects.
Alright so let's back up and see how different things are,
when we're working with an opacity mask.
I'll just go ahead and press Ctrl + Z or Cmd + Z
on the Mac, until we get back to the point
where everything on this layer is selected.
Next you want to go to the Transparency panel.
So everything that we're talking about
throughout this chapter exists in this one panel.
And notice right there, we've got this button called
Make Mask.
Just go ahead and click on it,
and notice now we get a very soft transition,
consistent with that Gaussian Blur.
I also want you to take a close look at these thumbnails
here inside the transparency panel.
Notice that in addition to the image thumbnail,
which we saw just a moment ago
I'll go ahead and press Ctrl + Z or Cmd + Z on the Mac,
at which point we are seeing everything inside
the document in this tiny thumbnail,
but then if I press Ctrl + Shift + Z,
or Cmd + Shift + Z on the Mac, to redo that operation,
we now have an additional thumbnail
over here on the right hand side, which represents
the opacity mask itself.
And notice that we have a white ellipse surrounded by black.
And this is just the way things work with layer masks
inside Photoshop.
So anything that's white inside the mask reveals,
and anything that's black like that fuzzy stroke conceals.
I also want you to notice something else,
that's going to throw you over time.
Because it's a little inconsistent with how things
generally work inside Illustrator.
Notice inside the image layer, we now have a group.
It doesn't tell us it's a clipping group.
It doesn't tell us it's an opacity mask group
or anything like that.
It just says the word group.
And if you twirl it open,
you're just going to see the placed images.
You're not going to see that elliptical mask.
The only way you really know that you have an opacity mask
is by the appearance of this underline.
It's either going to be a dotted underline or a solid one,
in which case you can consult the Transparency panel,
where you'll actually see the opacity mask represented
by this thumbnail.
Now if you want to edit that opacity mask,
then you click on that right hand thumbnail,
at which point notice what's happened
inside the layers panel.
All of the layers have disappeared
and we now see layers and in parenthesis opacity mask.
And we have what amounts to a single layer that contains
this ellipse.
You can't create anymore layers inside the mask,
which is why all these controls at the bottom of
the layers panel are dim.
And you're also going to see a little bit of a highlight
around that right hand thumbnail.
In which way, notice the ellipse is selected
and I could go ahead and switch to the Appearance panel,
which you can also get by choosing the Appearance command
from the Window menu.
Then I could click on Gaussian Blur
and I could take that value up to let's say eight pixels
this time around, click okay,
and that will give us a fussier transition.
Now a couple of other things I want you to notice.
See this Clip checkbox right there.
If you turn it off, then everything outside of the mask,
in our case, this ellipse, will become white
and it will end up revealing the model in the background.
So that only the black stroke is hiding her
and revealing the violet gradient.
If that's not what you want, if you want everything
outside the ellipse to disappear, then turn that
clip checkbox back on.
You also have this Invert Mask option,
which is going to invert how things work.
So in other words, white is going to conceal
and black is going to reveal
and then we once again have clipping outside the shape.
You can also turn Clip off, in order to see what
things would look like, if you're only
masking away her face.
That is not of course remotely what I want.
So I'm going to turn the Invert Mask checkbox off,
and I'll turn the Clip checkbox on.
A couple of other things to know.
If you want to see the mask here inside the document window,
instead of seeing the illustration, then you want
to press the Alt key or the Option key on the Mac
and click on that Mask thumbnail.
And you will see the mask all by itself.
Now it's going to look different than it does in the thumbnail.
You're going to see the ellipse against a white background.
But because the Clip checkbox is on,
Illustrator is clipping everything outside of that shape.
If you want to see the illustration again,
then just Alt or Option click once again
on that right hand thumbnail.
And by the way, that's exactly how things work
with layer masks inside of Photoshop.
Here's something else that works the same.
If you want to turn the mask off,
then just go ahead and Shift + Click on it
at which point, you'll see this big red X.
If you want to turn it back on, Shift + Click again.
And incidentally you also have a command that's available
if you click on a flyout menu icon,
in the top right corner of the Transparency Panel,
right there notice if you chose Disable Opacity Mask,
that's the exact same thing as Shift clicking on
this thumbnail.
Alright, I'm going to Shift Click to turn it back on
and finally if you want to be able to regain access
to all the layers inside your illustration,
then just to see this happen, I'll go ahead and switch
back to the layers panel and I'll click on the left hand
thumbnail, at which point all of your layers will reappear.
And that is my introduction to how opacity masks
work here inside Illustrator.
In the next movie, we'll use an opacity mask
to mask these glasses.