Thank you for replying!
I tried parenting a solid to the phone by holding down shift and pick-whipping a null. Then making that solid a 3D layer. I scaled and rotated the solid to fit the screen, but it won’t stick. The phone is animated; it’s rotating from the left to the center. I think I neglected to mention that it’s the screen I’m trying to matchmove.
I also tried the expression, but I think I got that wrong. I pasted the expression in the corner pin’s “upper left” property and typed in the name of the null in place of “locator.01”. The solid disappears from view as a 2D layer, but appears when it’s a 3D layer. Also, the points don’t stick in place.
I’m not sure what to do. I thought I could track with maya by baking locators for cases like this.