After Effects Grid maker
I was messing about with expressions in After Effects a while ago and this week I saw two people online talking about something similar to this, so I thought I'd post the expressions here...
Basically, you start with one layer in a comp, then add these expressions to position and to scale. Then when you duplicate that layer, say 9 times, you get a grid of 3 x 3 to fit your comp size. Then you'd just replace the footage in each layer as needed.
Position expression;
NumberAcross = Math.ceil(Math.sqrt(thisComp.numLayers));
W = thisComp.width/NumberAcross;
H = thisComp.height/NumberAcross;
gridPos = index ;
col = gridPos % (NumberAcross+0.0001) ;
row = Math.ceil(1/(NumberAcross/gridPos));
xPos = (thisComp.width/NumberAcross)*(col-1);
yPos = (thisComp.height/NumberAcross)*(row-1);
[(xPos+W/2) ,(yPos+H/2)]
Scale expression;
NumberAcross = Math.ceil(Math.sqrt(thisComp.numLayers));
xSize = (thisComp.width/width)*100/NumberAcross;
ySize = (thisComp.height/height)*100/NumberAcross;
[xSize,ySize]
Then duplicate the item 4 times, 9 times, keep on duplicating
Let me know if it works! Seems to...