[Dan Ebberts]

Try switching this:

.size[0].valueAtTime(1)

to this:

.size.valueAtTime(1)[0]

[Dan Ebberts]

So the straightforward approach like this doesn’t work for you?

function timeToFrames(theTime,theComp){
	return Math.round(theTime/theComp.frameDuration);
}
function framesToTime(theFrames,theComp){
	return theFrames*theComp.frameDuration;
}

[Dan Ebberts]

Try this for the precomp camera’s orientation:

L = comp("Main Comp").layer("Camera 1");
u = (L.toWorldVec([1,0,0]));
v = (L.toWorldVec([0,1,0])); 
w = normalize(L.toWorldVec([0,0,1])); 
sinb = clamp(w[0],-1,1);
b = Math.asin(sinb);
cosb = Math.cos(b);
if (Math.abs(cosb) > .0005){
  c = -Math.atan2(v[0],u[0]);
  a = -Math.atan2(w[1],w[2]);
}else{
  a = (sinb < 0  ?  -1 : 1)*Math.atan2(u[1],v[1]);
  c = 0;
}
[radiansToDegrees(a),radiansToDegrees(b),radiansToDegrees(c)]

[Dan Ebberts]

>for example, AE can’t let an expression to refer to its state in a previous frame or something like that?

That’s correct. However, it looks like your expression is already set up to loop through all previous frames (which is one way to work around the expressions-have-no-memory issue). You can take advantage of the time parameter of toComp() to get the frame-by-frame position of the target layer:

thisComp.layer("Target Layer").toComp(anchorPoint,framesToTime(cF))

and use that to calculate on the fly how the layer with the expression should respond on a frame-by-frame basis.

[Dan Ebberts]

It has limitations, but try this:

elev = degreesToRadians(75);
v = 1900;
e = .7;
f = .5;
g = 5000;
nMax = 9;
tLaunch = 1;
repeatEvery = 3;
nSegs = Math.floor((time-tLaunch)/repeatEvery);
vy = v*Math.sin(elev);
vx = v*Math.cos(elev);
t = (time - tLaunch)%repeatEvery;
tCur = 0;
segDur = 2*vy/g;
dSeg = 0; // x distance traveled
nb = 0; // number of bounces
while (nb <= nMax){
  dSeg += vx*segDur;
  vx *= f;
  segDur *= e;
  nb++
} 
vy = v*Math.sin(elev);
vx = v*Math.cos(elev);
if (time >= tLaunch){
  t = (time - tLaunch)%repeatEvery;
  tCur = 0;
  segDur = 2*vy/g;
  tNext = segDur;
  d = 0; // x distance traveled
  nb = 0; // number of bounces
  while (tNext < t && nb <= nMax){
    d += vx*segDur;
    vy *= e;
    vx *= f;
    segDur *= e;
    tCur = tNext;
    tNext += segDur;
    nb++
  }
  if(nb <= nMax){
    delta = t - tCur;
    x = d + delta*vx;
    y = delta*(vy - g*delta/2);
  }else{
    x = d;
    y = 0;
  }
  value + [x + nSegs*dSeg,-y]
}else
  value

[Dan Ebberts]

The best I could come up with is something like this. It will be approximate because you never know exactly what you’ll get min and max wise with wiggle. You’ll need to tweak ampAdjust (an amplitude multiplier) and offsetAdjust (to move the whole waveform up or down) after you see what you get if you need it to run exactly from minVal to maxVal.

freq = 10;
maxVal = 40;
minVal = -35;
loopTime = 3;
ampAdjust = 1.25;
offsetAdjust = -2;
t = time % loopTime;
amp = (maxVal - minVal)/2
wiggle1 = wiggle(freq, amp, 1, 0.5, t) - valueAtTime(t);
wiggle2 = wiggle(freq, amp, 1, 0.5, t - loopTime) - valueAtTime(t);
w = linear(t, 0,  loopTime, wiggle1, wiggle2)*ampAdjust;
offset = (maxVal + minVal)/2;
value + w + offset + offsetAdjust

[Dan Ebberts]

I think this should work:

L = thisComp.layer("Rect");
L.toComp(L.anchorPoint);

[Dan Ebberts]

Assume in your Master comp you have a layer named “Controls” with a point control named Box Position to control the position of the box in both precomps. You should be able to do it with an expression like this for each box position:

L1 = comp("Master").layer("Controls");
L2 = comp("Master").layer(thisComp.name);
p = L1.toComp(L1.effect("Box Position")("Point"));
L2.fromComp(p)

[Dan Ebberts]

Try it this way:

	$.writeln(testLayer.property(testProps[0]).numKeys);
	$.writeln(testLayer.property(testProps[1]).numKeys);

[Dan Ebberts]

Add this to the end of your expression:

createStyle().setFont(fontName).setText(layerTextOutput)