Problem With "Shadow" Track

OK, up front, newbie here. This is going to be a bit difficult to describe. I have a shot of a large sunflower which, about midway through the shot, dips its head out of frame then back in. After a lot of experimenting, I chose to break up the tracking into segments. I positioned the playhead to the right just after the sunflower stabilizes in size after coming back into frame (981 for sake of comparison later) and tracked it. (There are other tracks too; the objective here is to replace a somewhat thin line of background.) Track and remove went fairly well. I then moved the playhead to the first track (0) with a view to replacing the thin line of background coming in from the left and going to where the sunflower begins to dip down. Track went fairly well but here’s where the problem comes in. In doing the remove, I noticed that there was a certain amount of space near a sunflower petal that was not replaced even though the spline was clearly positioned such that replacement should have been made. Puzzling over this, I finally discovered that the tracking spline from the first track (as described above), was somehow in effect even though I did not use it to track at this point beginning at 0 (recall that one started at frame 981). OK, delete it and try again, i.e. re-outline and track. No joy; the certain small space was still not replaced even though the first track had been deleted. Checking the dope sheet revealed nothing, that is, there was no evidence of the presence of the deleted track. I cannot figure out why there is this kind of “shadow” from the first track that is preventing replacement from working as you’d think. The only thing I observed is that even though I did not begin drawing the spline the first time (frame 981), it shows up at frame 0 anyway. However, deleting it should remove all traces and yet, it doesn’t, I hope this isn’t too confusing and am greatly appreciative for any help. Oh, am using cleanplate exclusively as the replacement method; same cleanplate used for all actions described.

I think it might be easier to see the actual project (you can send an example here: martinb[at]

But what sounds like is happening is one of the following:

  1. One of your layers is masking the background or foreground, stopping the remove from happening. It looks like you tried to resolve this by removing the layer, but were unsuccessful.
  2. The sunflower is always covering a part of the background. Since you’re using a clean plate, this should not matter.
  3. Rendering artifact from the previous render. This is the most likely scenario, combined with point (1). When you have performed a remove you don’t like, it is best to “undo render” in the edit menu so the remove is reset, otherwise mocha may try to remove using the previously rendered frame.

I am happy to take a look at the shot (see email above) if you’d like to go over it.

Thank you for the help on this; clearly the newbie status was not an error! Guess it’s time to up the training game!