You can do it, but probably not the way you anticipated.
Make an elliptical mask on a solid, then double-click on the mask to enable the Free Transform tool. Put the center of the mask at the solid's anchor point. Now highlight the open mask path, copy it and paste it into the solid's POSITION property. Adjust the resulting position keyframes to taste; they default to a 2-second move.
I will give that a try dave. Thanks for hopping in here. I guess there is no straight away way to do it. Like a text layer. Rather a work around as you suggested.
Did you notice the second question?
Nope. But I shy away from Pan Behind anyway. I find it's a lot easier to just use a solid as a track matte and animate the solid's position. Boom. Done.
Thanks Dave, I still want to find out why my scenatrio is not working as I want it too. Instead of not using a tool, I want to understand it a bit more. Hence me doing these little practice runs. It will open me up to more avenues of creative flow if I can have an understanding of the tools and their parameters. Like WHY is my Mask shape panning instead of the Anchor point layer not animating? (see orig question)
I hope someone else chimes in with some REAL help for you. I've farted around Pan Behind.... oh, maybe four or five times since the tool first appeared.
Dave your instructions or work around are not clear to me.
"Make an elliptical mask on a solid, OK
then double-click on the mask to enable the Free Transform tool. <-- D.click the Mask in the comp, or the name in the TL?
Put the center of the mask at the solid's anchor point. <--the center of the eliptical on it's anchor point? The eliptical mask? Unclear.
Now highlight the open mask path, copy it and paste it into the solid's POSITION property. <--Unclear. There is only one mask path in your scenario where I have two in my question.
Adjust the resulting position keyframes to taste; they default to a 2-second move.
I think in other words it cannot be done having a shape mask follow an open mask path, that or you don't know, as I did not. I can use a solid and keyframe it manually. However I asked that in my opening statement.
Bump for clarity since I did not get an answer to either question... Can a Mask shape be instructed to follow a mask Path as a text layer can be? Or must I manually key the shape to the path without being able to use a first or last margin.
The other question is the anchor point behind a mask shape See above
You can make a layer follow a path that was originally created with the mask tools. You cannot make a mask path follow a motion path. There is no mechanism to lock all the vertices to a single path. Can't be done.
The information is not compatible. Vertex info for an animated path is vectors and angles relative to frame size and vertexes. Motion Paths are points in time based on composition space. While it may look like the same information at first glance the time factor in a motion path makes it different.
You can, however, attach the layer with the path to a motion path and then use that layer as a track matte. That would accomplish what you want to do as explained in the original post.
Thanks Rick. Thought it was undoable the way I wanted to do it. However I wanted to be sure, it was not me not knowing my parameters in regards to that. I know the work around however if there was a direct way I wanted to find out. You would know. I am sure. Thank you again for confirming my original question and suggestion for a work around. MY work around was draw the mask path and manually KF the shape (using the path as a guide) Lasso the KF's and interpolate them evenly via KF assist.
2nd Question Amigo...? Why is my pan behind affecting my shape on top?