Stopping Expressions to regain control of an object

[Noah Poole]

I’m no expression wizard, but I think I have a solution. You’ll need to tell it to use your expression if the comp time is less than where you want it to stop.

if (time < 1){; (wiggle(5,7)); }else{; transform.position} time < 1 is saying only do the wiggle before the 1 second mark. transform.position is saying to use whatever position keyframes are set. Sorry if I'm not explaining that well, but if you plug in your expression instead of the wiggle that should work.

[Mike Clasby]

You could just Split the Camera layer and then deactivate the expression, or use one of the three solutions below; expression on/off at a given frame, with a checkbox, or at given keyframes.

And here’s a nifty Dan expression for starting and stopping an expression at a given frame:

startFrame = 145;
stopFrame = 241;

if (time >= framesToTime(startFrame) && time < framesToTime(stopFrame)){ wiggle (5,20) }else{ value } ----------------------------- Name: Dan Ebberts Date: Jun 13, 2006 at 9:39:46 am Subject: Re: animating expression on/off On way is to apply a checkbox control to your layer, keyframe the control on and off, and add an expression like this to your property: control = effect("Checkbox Control")("Checkbox") ; if (control == 1){ wiggle(5,50); // your expression goes here }else{ value; } Dan ----------------------------------------- Name: julian06 Date: Dec 15, 2006 at 10:17:53 pm Subject: Re: Start Expression after certain frame hi let's assume that keyframe 1 is at frame 60 and the second on is at frame 240. Now add this expression if (time >= key(1).time&& time<=key(2).time) { wiggle(1,50) } else{ value }

[Mike Clasby]

Also… maybe this is a little easier, as you could slide the marker around as needed.

Marker Kills Expression
Set a marker with the asterisk key on the numeric pad.

n = 0;
if (marker.numKeys > 0){
n = marker.nearestKey(time).index;
if (marker.key(n).time > time){
n–;
}
}

if (n == 0){

//your expression here

}else{
value;
}

[Bryan Nieman]

Thanks for the quick response!

When I deactivate the expression on the new camera it loses the values from the previous frame. Is there a way to copy the calculated values from the initial camera?

[Bryan Nieman]

Thank you everyone! Great insight 🙂

I finally got a grasp on using key frames with expressions. Using if statements was the way to go for me but the other solutions are nice too 🙂

Take care,
Bryan

[Kyle Hamrick]

Depending on the situation, I tend to use slider controls for a variable I might want to do away with later (and/or change easily).

They’re easy to set up – pretty much just pickwhipping, and it’s pretty easy to make sure your object won’t “jump” when the expression is ended.

Kyle Hamrick

Editor/Motion Graphics Artist

http://www.kylehamrick.com