Use ease() expression with for loops

[Dan Ebberts]

At each frame, the result of an expression will be the last thing it calculates. What are you trying to get it to do?

Dan

[Dan Smith]

I have some pictures, which I add to the scene and into array.
I have a camera object, which moves from object to object with ease expression and object’s coordinates.

I need to move the camera from the first to the last picture consecutively with ease() or other. For e.x.: from “Name1” to “Name2”, from “Name2” to “Name3” etc. The number of interaction must be equal to the number of pictures.

So I try to use for loop to do it.
How can I do it in another way?

xInPos = thisComp.layer("Name " + i).transform.position[0];
xOutPos = thisComp.layer("Name " + (i+1)).transform.position[0];
x = ease(time, 0, 20, xInPos, xOutPos);
[x, value, value]

[Dan Ebberts]

What’s controlling the timing of the moves, comp markers? If so, you expression needs to figure out which two markers the current time is between and use that to determine how far along it should be in the ease between the positions corresponding to those two markers. Something like this probably:


m = thisComp.marker;
if (m.numKeys > 0){
n = m.nearestKey(time).index;
if (time < m.key(n).time) n--;
if (n == 0){
val = thisComp.layer("Name " + 1).transform.position;
}else if (n == m.numKeys){
val = thisComp.layer("Name " + m.numKeys).transform.position;
}else{
inPos = thisComp.layer("Name " + n).transform.position;
outPos = thisComp.layer("Name " + (n+1)).transform.position;
val = ease(time, m.key(n).time, m.key(n+1).time, inPos, outPos);
}
[val[0],val[1],value[2]];
}else
value


Dan

[Andrei Popa]

Let me see if i understand you correctly. You have a comp with a bunch of pictures(the number may differ over time) and a camera. And you want the camera to hover over all the pictures with a preset animation/focus time. If so, you can use this


animDur = 1;
focusDur = 0.5;
totalCycle = animDur+focusDur;
otherLayers = 1;
picsNumber = thisComp.numLayers-otherLayers;
sector = Math.floor(time/totalCycle);
x = (time < (picsNumber - 1)*totalCycle) ? ease(time, sector*totalCycle , sector*totalCycle+animDur, thisComp.layer("Name "+ (sector+1)).transform.position[0], thisComp.layer("Name "+ (sector+2)).transform.position[0]) : value[0];
[x,value[1]]


animDur is the duration of the movement from one picture to another;
focusDur is how much the camera stays on a particular picture;
otherLayers is the number of layers inside the comp that are not pictures named “Name 1”, “Name 2” etc
For your information, if you put the picture from layer 1 towards bottom, you can use this(i think this variant is actually faster):

animDur = 1;
focusDur = 0.5;
totalCycle = animDur+focusDur;
otherLayers = 1;
picsNumber = thisComp.numLayers-otherLayers;
sector = Math.floor(time/totalCycle);
x = (time < (picsNumber - 1)*totalCycle) ? ease(time, sector*totalCycle , sector*totalCycle+animDur, thisComp.layer(sector+1).transform.position[0], thisComp.layer(sector+2).transform.position[0]) : value[0];
[x,value[1]]


Andrei
My Envato portfolio.

[Dan Smith]

Thanx to all. I try to use these variants.