Continuous rasterization, footage size mismatches, whatever. We can't know. Your info is far too vague. Provide screenshots with exact settings visible.
Just in AE with my footage.
About to track in mocha.
Tracked in mocha (only tracked half because i didnt want to wait).
Adding a solid to paste my corner pin data to.
Masked it to where I wanted it.
Selected the type of data I wanted.
Copy to clipboard.
Great... the insert image thing grayed out.
Going to have to post the last pic separately.
Your workflow is wrong. Corner pin distorts and scales a layer to match the plane you tracked in Mocha.
You track in Mocha, adjust the planar surface in Mocha to match the plane you are tracking, export the corner pin data (copy to clipboard), paste to your solid in AE, and then draw your mask on the transformed solid. Mocha transforms the entire solid. There is no way for Mocha to know anything the size or position of the mask you you'll have to draw it after the layer is transformed. The layer can't be properly transformed unless you set up the planar data in Mocha.
If you want to mask in AE first then apply tracking data don't use corner pin. Use export position scale and rotation.
If you are trying to do some rotoscoping in Mocha then the technique is completely different. If that's what you are trying to do let us know or search for roto in Mocha tutorials.
I understand what you are trying to say, but i have been able to paste corner pin data on a masked layer before without any problems of rescaling. Also, in this video Andrew Kramer does it aswell with no problems.
In Mocha make sure you're at the first frame and click 'Align Surface' button to align surface corners with the full frame corners, then you will be able to paste corner pin data into your masked solid in AE as you want.
As I said before you have to align the planar surface (couldn't remember that it was called Align Grid because I was answering from memory) first. Andrew used the last frame to align the grid so the layer would be at 100% scale only on that frame. The frame you use to align the grid is the frame where you must draw your mask if you plan to draw the mask first.
If you don't use the last frame, or first frame to align the grid and you don't remember what frame you used then drawing your mask on any other frame will foul up the alignment and your mask will be scaled. By far the easiest thing to do is apply corner pin to the solid on the first frame, then find a good frame to draw the mask and be done with it.
Fix your workflow and you'll solve your problem. Align the planar surface and you're good to go.
I am still trying to fix this problem and none of the fixes work. so frustrating.
I FIXED IT! First, make sure your settings are the same, and in mocha ae preferences go to clip section and change the setting from linear to log. This worked for me after days of trying everything. I tried this on whim, and it worked. I'm also doing the video copilot tutorial called facemelt. I'm using Adobe CC 2015 w/ a new mac pro. I hope this helps someone. Also there is no align footage button in Adobe CC anymore so you can't hit that button.
The align panel still exists and functions as always. You can't align 3D layers automatically but you can align other layers based on their layer boundaries. I'm not sure how you would use align in this kind of project. As long as your comp, frame rate, and layer size are all correct Mocha corner pin to AE has always worked the same way. It's the same with corner pin tracking inside AE. Your 'corner pin' layer must be the same size as the video layer you are tracking for the corner pin to work.
Love to see your tutorial when it's done.
Also note, that the new MochaImport+ V5 allows to move AE masks directly with a mocha track using the "move properties" function:
In contrast to using transform data, it includes the shear and perspective information of a corner pin and hence is more accurate.
And compared to the "align surface + corner pin" approach it works in a single click and you don't need an extra matte layer but get an animated mask shape directly.
I take that back, it doesn't work. I have gone back for a week now the comments section in both posts are filled w/ the same problem w/ no fixes. I think it may be an Adobe CC2015 bug. I have a mac pro 2013 w/ 12 cores the message boards are full of ppl w/ the same problem. I'm stumped.
As Rick mentioned, the workflow you performed in the first post is not the correct way to paste the data. If you paste corner pin data to a layer that is not the same size as the Comp, it will scale down incorrectly.
In your case, you have applied a mocha mask data to the layer, which has reduced the size of the layer to the bounding dimensions of the shape.
The difference in Andrew Kramer's tutorial is he's aligned the surface in mocha for the tracking data layer to fit the full frame, and then he's applied the data again to the effect Pre-comp layer which is also the same dimensions as the comp. This is one of the ways you make sure the data is going to fit correctly. Just applying the mask then applying the tracking data is not going to work, because After Effect's corner pin bases its warp on the dimensions of the layer, not the comp.
See here for more information on how this works:
Take a look at the section called "Applying Corner Pin for Layers with different dimensions".