[Jeff Hinkle]

Select your Gradient tool (hit G on the keyboard if you can’t find the tool icon). Notice the toolbar across the top of your screen has changed. On the left side there will be a small representation of the current gradient, which is most likely your foreground color to your background color. Click on this gradient swatch and a drop down menu will show up with all the current presets. The second preset (unless you’ve changed them) should be Foreground to Transparent, which will be your foreground color fading to a gray checkerboard pattern. Select that one and set your foreground color to white.

Now click where you want your gradient to start, in this case about 10 pixels above the top of your selection. Keep the mouse button held down and drag to about 5 pixels below the bottom edge of your selection (holding Shift will constrain your drag to a straight line). Release the mouse and your gradient will be created.

—
It is easier to destroy than to create.
More fun, too.

[Jeff Hinkle]

What weird temporal properties are you getting? Bringing a layered Photoshop document into After Effects will generate a comp with each layer having its own set of properties (Scale, Position, Rotation, etc.) but they should all be set to their defaults with no actual animation. Was your original PSD document just a plain layered image, or had you imported video, or done some animation through Photoshop Extended’s timeline?

—
It is easier to destroy than to create.
More fun, too.

[Jeff Hinkle]

Almost forgot: Don’t forget to make a new layer in between building your selection and dragging with the Gradient tool. That’s the icon at the bottom of the Layers palette that looks like a little notepad with the corner folded over. Then when you drag with the Gradient tool, your gradient will go in this new layer and not on top of your existing image.

—
It is easier to destroy than to create.
More fun, too.

[Jeff Hinkle]

Just clicking on the layer won’t create a selection. I’m guessing earlier in the tutorial, he explained about CTL/Command-clicking (that’s CTL on a PC, Command on a Mac) the thumbnail of the layer in the Layers palette. That will load the opaque pixels of that layer as a selection. Then you should be able to use Modify>Contract.

The next step is saying, while you still have the selection available, select the Rectangular Marquee tool (that’s the one that looks like a box with a dashed outline) and use it to deselect the bottom part of the current selection. Hold down ALT/Option. Your icon will gain a little minus sign. Now if you click and drag, any area of the current selection you go over will be subtracted.

Then it’s just a matter of dragging with your Gradient tool with a white-to-transparent gradient. It will fill the shape made by the selection, white at the top, fading to nothing at the bottom.

Hopefully that helps clarify the points, and I didn’t make you feel like a dummy.

—
It is easier to destroy than to create.
More fun, too.

[Jeff Hinkle]

Put your black and white layer (we’ll call it A) above the layer you want to mask (B). Set the Track Matte (shows up as TrkMat in the timeline panel; you may need to hit the “Toggle Switches/Modes” button if you don’t see it) on layer B to Luma Matte. Anyplace that’s black in A will be transparent in B, anyplace white will be visible. Anything gray will give partial transparency.

Now, if A is a black layer with transparency, you’ll want to use an Alpha Matte. Same principle, but anyplace that’s opaque will be visible in B and anything transparent will likewise be transparent. If you’re going Alpha Matte, the opaque area color is irrelevant. It could be black, white, rainbow colored, a lovely photo of a sunset, doesn’t matter. All After Effects looks at is opacity.

—
It is easier to destroy than to create.
More fun, too.

[Jeff Hinkle]

With Pen tool selected, hold down Alt/Option. Your cursor will change to a little crooked “V” shape. Click and drag.

With the Move tool selected, hold down Ctl-Alt/Command-Option.

—
It is easier to destroy than to create.
More fun, too.

[Jeff Hinkle]

I believe the shortcuts are mostly if not completely identical. The few times I’ve had to go cross-platform, I don’t recall any shortcuts not working right. The basic conversion to remember:

CTL = Command
ALT = Option

One caveat: The modifier keys are in slightly different positions, so that may slow you down a little. Many’s the time I hit the Windows key while my hands were running on shortcut autopilot.

—
It is easier to destroy than to create.
More fun, too.

[Jeff Hinkle]

Your video size looks to be 720×480 SD, and your comp is definitely an HD comp. Not sure what your comp size is, but since your magnification is only 33%, I’m guessing it’s probably a 1080. Change your comp settings to match your video, or drag your video to the New Comp button in the Project window to make a comp at the exact size and pixel aspect ratio of your footage.

—
It is easier to destroy than to create.
More fun, too.

[Jeff Hinkle]

Sounds like you want the Graph Editor. Look for the little squiggle-line icon on the top right of your layer list in the Timeline. Select the parameter(s) you want to adjust, click the graph editor to access your motion graph, click again to get back to your keyframes.

—
It is easier to destroy than to create.
More fun, too.

[Jeff Hinkle]

You can still reconnect your footage even if it is precomped. Just go to your Project window and find the original sequence in the list. Right-click the file and select Replace Footage… and navigate to the original files. However, if by “precomp” you mean you actually rendered it out with the missing frames and imported the resulting movie file, then no, you can’t reconnect that. But you should still have your original sequence comp in your project that you can pull back in the original sequence files.

As to how could the links break without moving them? You’d be surprised. I’ve had entire multi-layer images go missing from AE overnight with the computer off. Computers like to mess with you sometimes. It’s their only joy.

—
It is easier to destroy than to create.
More fun, too.