How would i do this in expressions (link in body)

[Filip Vandueren]

I would do this with Motion Tile and Timedisplacement, instead of having mulitple layers.
Do you need the interpolation at the beginning where it zooms in and out, that makes it a bit harder…

For a “normal” mosaic with timelag this seems to work:

(Without expressions, but you could create a null with some sliders and some simple expressions to do some of the divisions for you)

– Add your footage
– Add a Motion Tile, change Tile Width and Tile Height. If you want a 4*4 grid use W= 25, H=25 (100/4)
– for even numbers, you’ll have to adjust the Tile Center so all tiles fully fall in screen. In my example that would work out to TIle Center= 12.5%, 12.5% of Comp Width

-create a solid.
– add a Ramp, default settings.
– create a second Ramp on top, and change it so it’s Black-White Left to Right.
– Note the number of Rows your mosaic has (in this case 4) set the Blend With original of the second Ramp to Rows*100/(Rows+1).
So in this case: 400/5 = 80% Blend
For 3 rows that would be 300/4 = 75% Blend
For some reason, this just works… I just figured it out with some trial and error.
– add a mosaic effect to your blended ramps and set it to H=4, W=4
– Add an Auto Levels Effect, Set all Clips to 0%
We now have a solid with greyscales boxes that are perfectly spaced from black to white. But because Time displacement like displacement works relative to 50% grey, let’s change this so all values are positive, i other words, above 50%grey or 127/255 grey
– add a levels effect and set output black to 127
– Precomp this gradient layer (move all attributes…), and hide the precomp in your maincomp

– Above your footage add a Adjustment layer with a timedisplacement effect,
– chose the gradient Precomp as the TD layer

now adjust Max Displacement to your taste, for a true 1 frame per tile effect use numTiles/FPS, for example 16/25
Set Time resolution to double the FPS of your Comp.

Note, you can enter these calculations directly in after effects, just click o the value so you can enter text, and then type 16/25, After Effects will use 0.64

There, that should work.

Let me know if this works out for you