Expert: Joseph Silver - 3/24/2007

Question
"Hello,
I have river clips which were shot on the boat, so a little of it
shake. I try to use "tracker control" in After Effect Pro but I'm sure about
"feature region ; search region and attach point". Please tell me how
do they work ?
Thank you so much.
Have nice weekend !"

Answer
Hi - The feature region is the area that is being tracked, and should enclose a distinct feature. For example, if you were on a boat, and there is a lighthouse in the distance that stands out against a very blue sky, you might want to surround the lighthouse in the feature region.

The search region is the area where AE will look for the feature region, and must be large enough to accomodate any motion in the camera. For example, if there is panning with the camera, you will want to make sure the search region is large enough to follow the lighthouse from frame to frame. In  your case, I imagine the camera was pretty locked, so the search region will probably not be so large. Try to keep search region as small as possible, as the larger the region, the longer the track takes.

The attach point is the place of attachment for the target footage.

Joseph Silver
www.designomotion.com