Mask Question...

[Mister Shan]

I am doing a tutorial on creating masks. The instructor is saying when you create or select a mask, you can use the arrow keys on the keyboard to soften or reshape the mask. For example softening the edges or changing a polygon into a triangle.

The thing is I do have some AFX experience and the arrow keys were always how you move a selected layer or mask. So whenever I select or create a mask I try hitting the arrow keys like he is telling me but all that is happening is it is moving around the composition. Any ideas?

[foughtthelaw]

if you have a link to the tutorial that might help. I've never heard of being able to change a mask shape into another shape by using the arrow keys. the normal behavior is as you described, arrow keys will move the selected points of the mask.

[Mister Shan]

It's on Lynda.com so I don't think you can access it, but here is the link.

Masks

But also here is the transcript where he talks about it.

"Let's go ahead and select that layer again. We'll switch over to our rounded rectangle, and it's a little like the rectangle tool, except now we have rounded corners, and we still have the same modifier keys, but we also have two additional functions here, so using the arrow keys on your keyboard, the up and down arrows will alter the overall roundedness of this shape, so by hitting up arrow we are increasing the roundedness, by hitting the down arrow we are creating more of a sharper corner.

The left arrow will make it completely sharp, whereas the right arrow will make it all the way rounded. So as I drag out here, I can hit the right arrow again and make it completely rounded until we get this pill shape thing. So let's go ahead and start it rounded here like this a little bit, and we'll increase the roundedness just a tad. Alternately, you can also hold down the space bar before you let go of the mouse button and what that's going to do is allow you to reposition your mask while you are still creating it inside our composition window, so let's go ahead and get that aligned nice and neat."

[Dave_LaRonde]

You can move mask path vertices around using the arrow keys.  Just select 'em and move 'em.

[Mister Shan]

No it's not moving the specific vertices. It's effecting the shape of the entire mask. I found this on adobe's help page.

Draw rectangles, rounded rectangles, squares, and rounded squares

Create and customize shapes and masks in After Effects

• Select the Rectangle tool or the Rounded Rectangle tool , and do one of the following:

  • To draw a rectangle or rounded rectangle, drag diagonally.

  • To draw a square or rounded square, Shift-drag diagonally.
• (Optional) If drawing a rounded rectangle or rounded square, do the following before releasing the mouse button:

  • To increase or decrease the corner roundness, press the Up Arrow key or the Down Arrow key, or roll the mouse wheel forward or backward.

  • To set corner roundness to the minimum or maximum, press the Left Arrow key or the Right Arrow key.
• Release the mouse button to finish drawing. If drawing a square or rounded square, release the Shift key after releasing the mouse button.

[Roei Tzoref · Accepted solution]

No it's not moving the specific vertices. It's effecting the shape of the entire mask. I found this on adobe's help page.

it refers to the mode you are in while you are creating the mask and not letting go of the left mouse button

try it: select a rounded rectangle for example, now drag a mask in the composition window. don't let go of the left mouse button. as long as you don't let go, you can use the arrows to reshape it. when you let go, it's baked in. if you know illustrator, it works in the same way.

BTW, if you do want to create a shape that you can modify in this manner, you should use shape layers. they can be parametric which means they are modified by parameters even after the fact. you have to choose it's either controlling parameters or controlling vertices.