Essentially I'm trying to create a mask that captures the image it encircles and allows me to distort the image. For example, if I have a picture of a person and draw a circle mask around the person's head, when I distort the mask it distorts (e.g. stretch/skew/bend) the person's head and not just the shape of the mask. I'm trying to create my own version of this video but using Motion instead of AfterEffects and Mocha.
If you watch the tutorial it's the AfterEffects "precompose" function that I'm trying to mimic. And I don't think creating a new Group in motion is the ticket because I can only distort the image by adjusting the edge of the canvas vs. the edge of the mask.
video's tutorial vimeo.com/benboutwell/frametutorial
Thanks for any and all help! It's been a couple of frustrating days...
Thanks Adam. I was using a mask to create the layer, but adjusting the mask layer resulted in exposing a different part of the image. So I created a mask of the image I wanted (i.e. the inside of the picture frame) and then exported that image and re-imported it (as you suggested above) but reimporting it created a layer whose edges are the full frame size. So in order to adjust the little cropped image in the middle I had to adjust edges of the frame instead of just the edges of the image. Sorry if that doesn't make any sense.
I used the motion tracking tools on the reimported image, but I didn't adjust the tracking points by hand, I let the program track the four corner points. It didn't do a very good job so I need to try it again by hand and see if I get different results.
My biggest question remains to be: Is there a way to create a mask that cuts out a layer of the image so that when I adjust the edges of the mask the original image it encompassed gets skewed and not just the edges of the mask. I'd like to do this without having to export the movie frame into an image.
Thanks again for your help.