I have tried that, but it only works if I don’t move the comp camera. The track matte is only cutting a 2D hole, so it looks weird if I do a camera move.
Here is a copy of my .mov file. I tried moving the anchor point, but it didn’t help with the masking. Right now it is just a positional move up on the y-axis to make the bars grow. They are a 3D pre-comp.
I would like to not have to keyframe scale if possible, as all of my other calculations are done based on y position.