On the main track I have a Christmas tree with balls.
On an overlay track I have a face, which I want to place in the ball. What I like to do is
Create a mask for the face.
Scale the overlay and position it over the ball.
Doesn't seem to work this way. What I did was I added the overlay track with the face. The face is of course not filmed to be on right spot on the screen, nor to be of right size. So I just add the mask and edit the mask to fit the face. Then I add the transparency effect. I get a nice overlay, where only the face is seen from the overlay track. Now I want to position and scale the face to fit the ball. I add the scale effect. But it doesn't scale everything I have so far on the track. It scales only the mask, but not the video with the face. This is not what I would call a chain. And when only the mask is scaled, even the boundaries of the mask frame get scaled. So if I have a nice oval spot for the face and everything around it is transparent, it is transparent only to the corners of the frame. Scaling down drags the corners inwards, making a non transparent frame, where the overlay video gets visible, because it didn't get scaled.
So what I believe I would have to do is I'd have to first scale the overlay video, then add the mask&transparency. But that is a pain! If I need to adjust the positioning, I have to go to the scale effect, then I have to adjust the mask. Instead of just creating a masked face, then scaling and positioning it. What am I missing here?