A frog sits in the middle of a shot. In the clip above, it's gone two seconds later, and the moss and water behind it keep moving with the camera, no blur patch, no wobble at the edges. After Effects already has the tools for this kind of removal. The question is where they hold up and where they don't.
The After Effects route
Content-Aware Fill lives right in After Effects, no Dynamic Link needed. Paint a mask over the object on one frame, and the panel fills the hole using nearby frames. Roto Brush speeds up drawing that mask by pulling a rough outline from a single click or stroke, and Mocha AE, which ships with After Effects, adds planar tracking so a mask can follow a flat surface like a sign or a patch of ground as the camera moves past it.
Where it struggles
All three tools are built around a short, fairly stable window. Once the object itself moves a lot, like the frog crossing wet ground, or the camera pans and tilts through the whole shot, Content-Aware Fill has to invent more background from less reliable surrounding frames. That's where a smear shows up, or a soft flicker where the fill loses track of what's actually behind the object. Mocha AE's planar tracking helps with flat surfaces, but an object that turns, is partly hidden, or leaves and re-enters frame still needs a mask that's tracked as a shape through time, not just a tracked plane.
The AI pass, when the shot keeps moving
The fix for a moving shot is the same idea as Mocha's tracking, taken further: track the object's full outline across the shot instead of patching each frame on its own.
1. Track the object, not one frame
Mask the object on a clear frame, then track forward and backward through the clip. Scrub the result and fix the mask only where it drifts, usually where the object turns, is partly hidden, or leaves frame.
2. Include the shadow and reflection
A removal that still leaves the shadow on the ground is the most common giveaway. Grow the mask to cover the shadow and any reflection before the removal runs.
3. Rebuild the background across the whole shot
Run the removal on the tracked region. The background behind it is rebuilt across time, so it moves with the camera instead of sitting on the image like a flat patch, which is what frame-by-frame fill tends to produce once anything in the shot is moving.
4. Round-trip back to After Effects
Export the result as an EDL, FCPXML or OpenTimelineIO file and bring it into your After Effects or Premiere Pro project. The comp work, grade and final delivery stay exactly where you'd normally do them.
Asking an agent to do the AI pass
Remove the frog from this shot. Track it through the whole clip, include its shadow, and keep the water and moss moving naturally. Show me the result before replacing the original, then export it as an EDL.
With the run mode set to review, the agent runs the removal and waits for your approval before anything replaces the original clip. You decide if it's clean, and the export is what lands back in your After Effects project.
When to just use Content-Aware Fill
If the object is small, the camera barely moves, and the shot is a couple of seconds, Content-Aware Fill with Roto Brush and Mocha AE will get there faster than setting up a separate pass, and you never leave After Effects. Reach for the tracked-mask route once the object or the camera is moving enough that you'd otherwise be fixing the fill by hand, frame after frame.
Download the free Shoty editor for the tracked-mask route. For the full workflow on moving objects, see remove object from video with AI, and for the masking step itself, AI rotoscoping.