Animating an arrow over moving footage
by DMick27
on
Nov 8, 2006 at 2:55:50 pm
I am trying to animate an arrow overtop of a road from about 20 seconds of helicopter footage. If the footage was still, I would have no problem. Animating a moving arrow, simulating the direction a car would be driving along this road, while the footage itself moves, is presenting a problem. Does anyone have any suggestions?
Re: Animating an arrow over moving footage by Dave LaRonde on Nov 8, 2006 at 5:24:54 pm
You have a time-consuming challenge in front of you.
If you've never done Motion Tracking, the scope of which is beyond a single post, get ready to use AE Help a lot.
I would start by constructing the ENTIRE path your arrow is going to have to travel. I would place the aerial footage on top of a REALLY big solid. On this solid I would create a mask of the road. As the shot progresses in time, I would move the mask to match it up to the road again, and create more mask vertices... repeating the process until the end of the shot.
Once I have a mask that represents the entire road, I'd then copy the solid, mask included, to a new comp that's the same size as the solid. I'd create my arrow and paste the mask into the arrow's position property to create a motion path for the entire road, and animate the arrow along the motion path. Now, turn off the solid -- make it invisible.
I would then take the resulting comp into the original comp with the aerial shot. Once I matched up the arrow's initial position with the beginning of the aerial shot, I would motion track the second comp to the aerial shot, changing tracking points as necessary.
Well, that's how I'd do it... any other suggestions?
Re: Animating an arrow over moving footage by DMick27 on Nov 8, 2006 at 5:29:59 pm
Dave, I have already started down that path. I was HOPING that there might be an easier way though! Once I had the masked road in place, I wasn't sure how I was going to take the motion track from there, but your post has shown me the best way to go. Thank you so much, I REALLY appreciate the time you took to answer. :)
