Re: auto scaling keyframes

Yes, I get it now:


l=thisComp.layer("control");

if (l.position.numKeys>=4) {
t2=l.position.key(2).time- l.inPoint;
t3=l.position.key(3).time- l.outPoint;

if (inPoint+t2>=time) {
TT=linear(time,inPoint,inPoint+t2,l.inPoint,l.inPoint+t2);
} else if (outPoint+t3>=time) {
TT=linear(time,inPoint+t2,outPoint+t3, l.inPoint+t2, l.outPoint+t3);
} else {
TT=linear(time,outPoint+t3,outPoint,l.outPoint+t3,l.outPoint);
}

l.position.valueAtTime(TT);
} else {
value;
}


OK this looks a lot more complex, but it's not really:

first check if there are 4 position keyframes, otherwise we would get errors and this stuff wouldn't work.
There are 3fases:
-from the layer's inPoint to the 2nd keyframe,
-from 2nd to 3rd keyframe
-from 3rd keyframe to the layer's outPoint

so there are 3 if/then's to check in which stage of time we are now,
the correct corresponding time TT on the controlLayer is calculated with linear(), then we sample the value at time TT.

I suppose Keyframe 2 and 3 are identical ? A move in, and Move out, but this expression will work if they're not.
The expression will not work correctly if the new Layer has a length that's shorter than the moveIn + the Move Out (in your case 24 frames)