<p>In these cases, I generally precompose the layer and apply the mask to the precomp (the layer is animating inside the precomp)</p>

CC BY-SA 3.0
2013-12-15T00:13:38.670Z
2013-12-15T00:13:38.670Z
Julien Altieri
<p>I found this post helpful: <a href="http://forums.adobe.com/thread/704283" rel="nofollow">Preventing a Mask From Animating</a> </p>

<blockquote>
  <ol>
  <li>Create a comp size solid above your text layer.  </li>
  <li>Apply the mask to the solid.  </li>
  <li>Set the <strong>Track Matte</strong> setting of your text layer to <code>Alpha Matte</code>.</li>
  <li>The text layer will now adopt the alpha channel of the masked solid.</li>
  </ol>
  
  <p>You can freely animate the text and mask independently.</p>
</blockquote>

<p>I did not know the name of what I was trying to do. I needed to convert the mask layer into a <code>Track Matte</code>. </p>

CC BY-SA 3.0
2013-12-13T18:21:40.653Z
2013-12-13T18:21:40.653Z
ckpepper02
<p><strong>After effects</strong> noob here. I'm working on an animation where a ball falls through a hole. I created a <code>Shape layer</code> to use as the mask, but I can't get it to mask the ball layer.</p>

<p>I've also tried adding a mask directly to the ball layer, but it moves with the rest of the animation. Is there a way to turn the mask on and off without affecting the rest of the animation?</p>

<p><img src="https://i.sstatic.net/J717t.gif" alt="Ball not being masked"> </p>

<after-effects>
How to mask an animated layer in After Effects?
ckpepper02
# How to mask an animated layer in After Effects?

(Asked by: username_0 on 2013-12-13)

**After effects** noob here. I'm working on an animation where a ball falls through a hole. I created a `Shape layer` to use as the mask, but I can't get it to mask the ball layer.

I've also tried adding a mask directly to the ball layer, but it moves with the rest of the animation. Is there a way to turn the mask on and off without affecting the rest of the animation?

![Ball not being masked](https://i.sstatic.net/J717t.gif)

**Tags:** after-effects


---

## 2 answers

### Answer by username_0 on 2013-12-13. Score: 4 | Accepted answer

I found this post helpful: [Preventing a Mask From Animating](http://forums.adobe.com/thread/704283)

> 1. Create a comp size solid above your text layer.
> 2. Apply the mask to the solid.
> 3. Set the **Track Matte** setting of your text layer to `Alpha Matte`.
> 4. The text layer will now adopt the alpha channel of the masked solid.
>
> You can freely animate the text and mask independently.

I did not know the name of what I was trying to do. I needed to convert the mask layer into a `Track Matte`.


---

### Answer by username_1 on 2013-12-15. Score: 1

In these cases, I generally precompose the layer and apply the mask to the precomp (the layer is animating inside the precomp)


---

