Got it,
Sorry if this is a bit a convoluted explanation, it’s a tough one…
What happens is the shirt fine pattern is hard to exactly match so it looks more blurry in the middle frames and in 6 seconds you have plenty of time to notice… Conceptually first, imagine you have 2 checkerboards, and the top one is 50% transparent, if they are not aligned, you get grey levels – which is what you perceive as blurred.
What I tried: First I tried “Auto Align” ON which made it a bit more clear but upon render it was a bit noisy, so I raised Anti-Aliasing to 2,2 (of course to judge noisy you have to look at 100%)
Now that created artifacts on the hand on the right side of the frame (well the shirt under it). Since you have all the mask splines already, you might consider 2 passes and composite the best part of each for a final. That is leave the left side of her body (right side of the frame) without Auto-Align…
Another thing about Auto-Align, it will work better if in the precomp, you don’t clamp values (to see I placed in your precomp an adjustment layer, turned the project to float, and on that layer added HDR Compander with gamma 4.0). Actually I tried turning off your color correction settings in the precomp, turning up gamma in Compander and back down after RE:Flex… and it helps a bit Auto-Align. However it’s still a bit blurry.
The arm on the left side of the frame has some issues as well – in the first frame, it’s over the shirt and not the second frame. I would simply make a track matte for that at first and last frame that leaves an hole, and use the pixels of the last frame to make a reasonable background under her. If it was only a few frames I would say use the per shape blend feature, but your sequence is so long, that it might not work as advertised.
So you might consider: 1) doing your color correction after the effect, somehow pre-lifting the luminance before the effect, and working in float for that so you don’t clamp and can remove that luminance lift after the morph 2) Applying a smoothly animated sharpen is probably an idea here, you know that the smooth frames are in the center of your morph, so there would be no sharp at first and last frame, and you set the max sharpen on the center frame so it visually matches. The key is to have a Sharpen that has a threshold value (a maximum deviation from the original) like our SmoothKit Sharpen, there might be something like that in AE, not sure.
Hope this is of some help.
Pierre