How to animate a portion of a frame in after effects

[Silakos]

The problem is simple. I want to animate (specifically move) a specific portion of a frame to another section of the video.

In other words imagine a 10s video which consists of an image with a sky with clouds, and I want to take a cloud and put it in a different section of the sky. And because it just so happens the the sky's color is consistent I can fill the gap with the sky's color without making it look funny. In my case it's not a cloud but it's something equivalent.

I thought about cropping the cloud in the image in Photoshop put it on top of the original layer image in after effects and move it and mask-subtract the cloud from the original image and put a sky color behind to fill the gap. This is what I am going to do if the isn't another way.

[davidarbor · Accepted solution]

You're halfway there. Instead of going to Photoshop:

1) Mask the cloud and set the Mask Mode to Subtract

2) Duplicate the layer and switch the mask on the duplicated layer to Add

3) Add a Solid layer below both video layers and match the color to the sky

4) Animate the top layer, which should now just be your cloud.

[Silakos]

Thx a lot. I did it the photoshop way but your way has far less steps. I had 2 problems applying it though.

1. I cant find an equivelant to the magic wand tool in after effects and my selection with the pen can never be as accurate or as fast as that
2. For some reason masks dont seem to work like they are supposed to. I've used masks in the past and the add, subtract options worked perfectly. But in this composition for some reason the add option gives me a blackscreen, (in my case sky screen because I have put a sky color layer behind) and the subtract option doesn't do anything, just if I hadn't put a mask at all or if my mask was infinitesimely small.

[davidarbor]

1) The closest thing to the Magic Wand in After Effects is the Roto Brush, but that would be very inefficient.

2) Do you have multiple masks on the same layer that could be conflicting? Can you post a screenshot of your timeline with all the properties exposed? Or better yet, would you be ok with running the Collect Files command from File>Dependencies>Collect Files and posting a zip of everything?

You can also make your Magic Wand selection in Photoshop, right-click in the middle of the selected area, choose "Make Work Path" and then copy that path and paste it on your layer in After Effects. The mask might be pasted into the middle of your comp, so you'll have to double-click on it and reposition it, but it will work. You might also get some extra masks (from the Magic Wand selection) that you can delete.

At this point, it might just be easier to do the work in Photoshop, create a separate layer for the cloud, and then import the entire PSD into After Effects. If you do this, make sure to choose the "Composition-Retain Layer Sizes" option instead of choosing "Footage." This will create a comp with all the Photoshop layers, and you'll start out with a dedicated cloud layer.

[Silakos]

I don't have other masks. this happens with every new mask I do in whatever time of the time line I do it and in all sections of the screen.

Paper is what we used to call "sky". the cloud was an example. It was the easiest example I could give to get my point across.

[Rick Gerard]

In both screenshots you have your mask set to NONE which means no mask. Have you read the help files on masking? If not, please type masking or mask in the search help field at the top right corner of AE and do a little studying.

Cropped screenshots or screenshots that don't show us all that you have modified are not very helpful. Select the layer that is giving you problems, press the U key twice to reveal all modified properties of that layer, make sure masks are visible in the composition panel (the icon for mask paths should be lit up) and then Print Screen and paste to the reply field, or if you are on a Mac Shift+Ctrl/Cmnd + 3 and drag the screenshot to the reply field.

If all else fails start a new comp, add a single solid, select the pen tool (g) and draw a bezier mask and make sure you close the path. If the mask works there and it doesn't work on your video layer then either something is turned off, or you are using RayTraced or C4D rendering (masks and not supported if effects or CR is turned on - you should have seen a warning)

[Silakos]

I found the problem. The detail preserving upscale effect was upscaling the mask. I assumed that the mask was being uplied to the upscaled video but it was applied to the normal video and was being itself upscaled as well. Which means that it was going off the composition panel since the upscale was pretty big (from FHD to 4K). And that's why I couldn't see it