text layers are different from pixel layers. render order is different for these type of layers and the effects render after the transform causing this unexpected behavior. you would want to precompose the text layer, crop the compositing to the text it inside the precomp - and then apply the distortion in the master comp.
I've applied the Corner Pin effect to text layers before and it's worked fine. I don't know what makes this different...
I've also tried the precomposing option, but that removes the motion tracking. I want the text to follow the ball as it shifts around the frame. If I precompose, it stays in one spot.
UPDATE: So my problem was I wasn't precomposing the text layer along with the 3D tracker camera. Once I did that, it tracks the motion and the corner pin works just fine. Still don't understand why it worked before and is suddenly being so picky...ah well. Thank you!
So my problem was I wasn't precomposing the text layer along with the 3D tracker camera
you don't have to. you should precomp the text layer as 2d. make it big enough. then in the master comp set it to 3d and it will act as any other pixel 2d layer.
I did that, but it no longer followed the ball as it shifted around the frame. Pre-composing it with the camera let it track the ball.
Either way, I got it to do what I needed to do. It was definitely more of a fight than I would have preferred.
1. Add a text layer to the composition. Not through the 3d camera tracker. Leave it as 2d
2. Precomp the text layer
3. Crop it using the composition settings or the region of interest technique
4. In the master comp create a 3d null from the 3D camera tracker. Set it to where you want your text to stick
5. Set the text precomp to 3D
6. Hold shift as you parent the text layer to the null. It will now shift to the nulls position
7. You can delete the null
8. Add the corner pin effect to the text