<p>You need to rotoscope every object in front of your "background". There is not simple solution, because AE cant tell the difference between you foreground and background. Even I can't tell, because people drop shadows on your "background", etc.</p>

<p>You can try to use <a href="https://helpx.adobe.com/after-effects/using/roto-brush-refine-matte.html" rel="nofollow noreferrer">rotobrush</a> for that, but if you have there a lot of people, it will require a lot of work.</p>

CC BY-SA 3.0
2017-03-01T23:20:28.747Z
Ok but once I track the motion of the person coming in front what do I do with him to tell AE "this person shouldn't be affected b the mask"
phadaphunk
CC BY-SA 3.0
2017-03-01T23:26:13.373Z
Put it in a new layer above your video and adjustment layer. So adjustment layer can't affect it.
Shultc
CC BY-SA 3.0
2017-03-01T23:14:41.013Z
2017-03-01T23:14:41.013Z
Shultc
<p>I have this shot which has the right door color corrected to make it look dark and red :</p>

<p><a href="https://i.sstatic.net/4IEmQ.jpg" rel="nofollow noreferrer"><img src="https://i.sstatic.net/4IEmQ.jpg" alt="enter image description here"></a></p>

<p>How would I go about making it part of the "background" so that when someone comes in front of it, he is not affected by the correction like in the shot below :</p>

<p><a href="https://i.sstatic.net/yyGHY.jpg" rel="nofollow noreferrer"><img src="https://i.sstatic.net/yyGHY.jpg" alt="enter image description here"></a></p>

<p>I tried looking into Masks as background or 3D layers but couldn't seem to find what I'm looking for. I'm sure it's an easy thing to do but I just need guidance on what to look / search for.</p>

<video><after-effects><video-editor><mask>
Making background element out of a part of a video
phadaphunk
# Making background element out of a part of a video

(Asked by: username_0 on 2017-03-01)

I have this shot which has the right door color corrected to make it look dark and red :

[![enter image description here](https://i.sstatic.net/4IEmQ.jpg)](https://i.sstatic.net/4IEmQ.jpg)

How would I go about making it part of the "background" so that when someone comes in front of it, he is not affected by the correction like in the shot below :

[![enter image description here](https://i.sstatic.net/yyGHY.jpg)](https://i.sstatic.net/yyGHY.jpg)

I tried looking into Masks as background or 3D layers but couldn't seem to find what I'm looking for. I'm sure it's an easy thing to do but I just need guidance on what to look / search for.

**Tags:** video, after-effects, video-editor, mask


---

## 1 answers

### Answer by username_1 on 2017-03-01. Score: 1 | Accepted answer

You need to rotoscope every object in front of your "background". There is not simple solution, because AE cant tell the difference between you foreground and background. Even I can't tell, because people drop shadows on your "background", etc.

You can try to use [rotobrush](https://helpx.adobe.com/after-effects/using/roto-brush-refine-matte.html) for that, but if you have there a lot of people, it will require a lot of work.

> **Comments:**
> **username_0**: Ok but once I track the motion of the person coming in front what do I do with him to tell AE "this person shouldn't be affected b the mask"  
> **username_1**: Put it in a new layer above your video and adjustment layer. So adjustment layer can't affect it.  

---

