I am running into an extremely frustrating issue when using the Track Matte Key feature to mosaic license plates. Now, in the particular scene I'm working on, the plate isn't even moving, and the process should be quite straightforward.
What I am doing is:
1. duplicate the clip, so it occupies Video 1 and Video 2.
2. Create a title. Using the pen tool, create a shape over the license plate and set it as "fill bezier." Goes in Video 3.
3. Apply the Track Matte Key to Video 2. Set the Matte for Video 3.
4. Apply Mosaic to Video 2. Adjust the level so the license plate is unreadable.
Generally, thats it.
BUT- For some reason, even though it will look perfect at first, when I come back to the clip later, sometimes, RANDOMLY, the entire clip will be mosaic, instead of only the matte area. I double check my matte and all my settings, it all looks like it should... ithe settings are the same as the clip right next to it which is FINE. Even more mind boggling - sometimes for just a single frame, the whole clip will be mosaic, but the rest of the clip will be fine. what??
Now at first I thought this was happening because I was taking shortcuts by copying one clip from video 2 and applying the attributes to another clip, that should work as a timesaver right? sometimes it seems to. but I stopped taking the shortcut to see if this fixed the problem. Nope. Also, it seems that whenever I adjust the title clip in video 3 (make it longer, for example), this activates the bug or whatever it is.
IS this a bug or am I doing something wrong? I am at the end of my rope.
For the record, I did somehow manage a perfectly fine sequence with multiple clips of a moving license plate.
Oh well, I ended up just having to create a new title for each clip (about 30 of them) even though the place that needed to be blurred was the same across clips, so it felt like a lot of uneccessary work. This elminated the problem, but I don't think its a worthwhile solution to the issue.