I am trying to remove a flapping band-aid from a dancing guy's face. I followed Tristan Nieto's excellent directions in response to a similar query. I pasted what he suggested below.
I'm still having a problems though. I have to use several solids as Tristan directed and one is a patterned scarf. The pattern in this solid changes from shot to shot. I've tried doing this several ways, setting only one keyframe for each of the 4 gradient points, and setting several. I get the same problem of a scarf pattern overlay that changes each frame. Individual frames look great but playback shows an area where the scarf pattern seems to be boiling.
I'm not so smart with tracking or expressions, so would appreciate fix suggestions that are carefully spelled out. In Tristan's directions, I'm not sure how to Motion Track an object, so did mask my solids frame by frame manually. I don't know what he means by "find the right transfer mode for the job" and I don't know how to do the Expressions part of his suggestion.
Here is what Tristan suggested:
This might not be the answer you were looking for, but I've never had any success doing the frame-by-frame method for the exact same reason. My Best advice is to go back to AE and try the following.
Motion track the offending logo.
Make a small solid that's big enough to cover it, with a bit of room around.
Draw a mask roughly the shape of the logo and feather it. This'll probably take some keyframing, but if you can track the scale and rotation of the logo as well, this will cut out some of the work.
Chuck a 4 colour gradient filter onto your solid. Look at your video, and pick four points around the logo (but not on it) that reflect the average colour of the Golf Bag. Track these points (or just follow them manually) and then using the expressions sampleImage() expression, set the four colours on the grad filter to equal the colour of those four points on the bag.
After that, find the right transfer mode for the job, match the grain with the match grain effect and you should have something worth looking at. You could probably use this method to get rid of the jumpy jaggedies too, but this method has never let me down
> I'm not sure how to Motion Track an object
Start here for information about motion tracking.
But, really, I recommend starting here if you're new to After Effects. You really have to get a good grounding in the basics before you try something complex---especially something photorealistic and complex.
> I don't know what he means by "find the right transfer mode for the job"
He was referring to blending modes. The term 'transfer mode' is a legacy term for 'blending mode'. Choosing the right blending mode can really help to... well... blend two composited items together. See the page that I linked to for instructions on choosing a blending mode.
Todd, thanks for the reply. I'm not new to AE but am to some of the new efx and terminology. I will check out your links and see if changing the blending modes helps eliminate the boiling effect. Another suggesting I got was not to lay a solid over the offending band-aid but rather to cut a hole around it and put the original shot underneath so that I might use parts of that shot to fill in. So, I have some things to try before I nail the solution.