The problem is that I have two pictures of faces that are about 25% different in scale, and I'm trying to get them close to matching so that the morph looks good.
I found a few workarounds on Creative Cow, but none of them seemed to work for me:
1) Pasting the mask into a solid then resizing the solid appropriately, then pasting the new mask from the new solid into the other image.
2) Using keyframes with mask shape to scale the mask directly
3) Highlighting the mask using the common shape tool (unsure if they're talking about the rectangle shape tool here, Google revealed nothing), and then resizing the selected area.
Here's the link from Creative Cow with all these ideas:
Just to make it more concrete, one image is scaled to 75%, and the other to 110%. When I paste the mask from the 75% image to the 110% one, it appears too big -- as if it had been drawn on a 100% version of the image. And when I paste the mask from the 110% one onto the 75% one, it appears too small.
And I'm sure anyone who could answer this question already knows this, but the Reshape effect requires each layer to have two masks on it, one for the image that you start off with and one for the image you end with.
Pre-compose your scaled images and work on the pre-comps, not the original sources.
The mask paths are calculated in relation to the layer size. Scale up the layer and the basic mask information, the vectors used to draw the path, scale with the layer but the root data does not change. Draw a 50 X 50 pixel mask on a layer that is 50 X 50 pixels, copy the path and then past it on a layer that is 500 X 500 and they will be the same size. Now draw a different mask on a 50 X 50 layer that has been scaled 1000% and then paste it to a layer that is not scaled and see what happens. Return the original scaled layer to 100% and check out the size of the two masks. They should be the same.