Perspective Corner Pin Motion Tracking Problem
by Alex Vlair on Feb 12, 2013 at 1:44:31 pm
I've got a problem for you. So I have a video of a white square that slowly rotates. I want to add an image on top of that white square, and make it appear as if the image was attached to the square (essencially, I have to the two rotate together). I tried animating the
rotate by hand, but of course the motion doesnt add up perfectly, making it look less convincing than I'd like.
I suppose my only solution here is motion tracking? I tried to do a Perspective Corner Pin motion track, but was only met with grief and sorrow. I placed the four tracking points in each corner of the square I'm trying to track, and the motion trackers followed them okay. However, when I apply the track to my footage, for some reason the size of the image gets skewed (a lot smaller, and a bit stretched). Furthermore, the track itself is very jittery. I tried to apply a motion stabilizer to counteract the jitter, but it just made my text a little bit blurry and not much else.
I figured that the reason the image was getting skewed by the tracker was because, for some reason, the corner points being applied to my target image are based on the tracking points, shrinking down the target layer. So, I took the keyframes and opened them in Excel and did some math to come out with what should have been the correct corner points- however, when I put the new keyframes into after effects, although the size of the image was fixed, all motion was lost (despite the corner points moving).
I am completely stumped. Hope someone has a tip or two! Thanks!