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force a var to stop updating every frame
hi there,
is there a way to store the current time in a variable, when a specific event happens. or in other words: can i force a var to stop updating every frame?
in detail:
i have a keyframed slider control (1900 … 2000)
i have a bunch of layer which names goes like that: 1902_…/1904_../…with the following expression i set the opacity:
n = thisLayer.name;
a = n.split(“_”);
e = a[0];
if(e<=thisComp.layer("SLIDER").effect("SLIDER")("Slider Control")) 100; else 0;so far so good.
now i want that, if the layer’s opacity jumps to 100, the layer scales from 0 to 100 which would look like this:
ease(time, timeAtEvent, timeAtEvent+20, 0, 100)
tried to store the time in a variable in different ways (if else/while,…) but couldn’t get the variable to stop updating when the event shown above happens.
somebody got an idea?
thanks a lot -
2 Replies
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Variables don’t survive from one frame to the next, so your scale expression needs to figure out how long it’s been since the event. It will look something like this:
if (transform.opacity >= 100){
eventTime = time – thisComp.frameDuration;
while (transform.opacity.valueAtTime(eventTime) >= 100) eventTime -= thisComp.frameDuration;
t = time – eventTime;// calculate scale here based on t
}else{
value
}This expression assumes that opacity starts out at less than 100%. If you have it set so that it’s always 100%, the expression will time out looking for the transition, so don’t apply the expression until you’ve keyframed the opacity (or modify the expression to check for that condition).
Dan
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Thanks a lot Dan.
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