-
Switching between 2 position leaders with a slider
Hello!
I’m trying to set up a slider that would control how much a layer should follow the movement of 2 separate “leader” layers.
When the slider is at 0, it should follow the movement of layer A, and at 100% it should follow the movement of layer B. That would be perfect, but if it is easier to set up the expression with 2 sliders I’m ok with that.
What I got so far is an expression that works, only that it follows the POSITION while I need the MOVEMENT to be captured. So now I can set up a slider % and then the starting pos of my target layer, but can’t animate the slider cause it just moves the layer closer or away from the starting point.
So my question is:
how can I track the movement of a layer? must I write some expression that checks for a layer’s pos changes between frames, and start from there? -
4 Replies
-
try this:
a = effect("Slider Control")("Slider");
p1 = thisComp.layer("Leader1").transform.position;
p2 = thisComp.layer("Leader2").transform.position;dX = p1[0]-p2[0];
dY = p1[1]-p2[1];p1-([dX,dY]*a/100)
Kevin Camp
Senior Designer
KCPQ, KMYQ & KRCW -
slightly modified (clamped values for the percentage to be between 0-100, and simplified the distance calc.):
a = clamp(effect("Slider Control")("Slider"),0,100);
p1 = thisComp.layer("Leader1").transform.position;
p2 = thisComp.layer("Leader2").transform.position;d = sub(p1,p2);
p1-(d*a/100)
Kevin Camp
Senior Designer
KCPQ, KMYQ & KRCW -
I think you’re looking for something like this:
s = effect("Slider Control")("Slider");
accum = 0;
for(f = timeToFrames(inPoint); f <= timeToFrames(time); f++){
t = framesToTime(f);
vA = thisComp.layer("Layer A").transform.position.velocityAtTime(t);
vB = thisComp.layer("Layer B").transform.position.velocityAtTime(t);
v = linear(s.valueAtTime(t),0,100,vA,vB);
accum += v*thisComp.frameDuration;
}
value + accum
Dan
-
Hi Thomas
here’s what i use for this purpose, and it works the same for both 2D and 3D.
i find it very easy to read and manipulate.
for me this has worked in complicated settings, such as rearranging multiple layers across different comps (fun!!).best,
ylead1 = thisComp.layer("leader1").transform.position;
lead2 = thisComp.layer("leader2").transform.position;
select = effect("Slider Control")("Slider");linear(select, 0, 100, lead1, lead2)
Reply to this Discussion! Login or Sign Up