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Linear wipe completion to Light Sweep centre position...

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Steve Blacker
Linear wipe completion to Light Sweep centre position...
on Nov 5, 2010 at 1:21:33 pm

Hi there:

I'm working on a project, part of which is set up as follows:

Text layer animates on using Word processor preset, then wipes off the screen using Linear Wipe.

I'm also animating a light sweep with the Linear Wipe as that's the look the client likes.

Right now, I'm animating the light sweep manually to follow the wipe as it wipes the text off. I figured (since I have a ton of these to do) it would be great if I could somehow tie the light sweep position to the position of the linear wipe completion. I managed to get it to work - sort of - by pick-whipping the light sweep to a null object, then pick-whipping the linear wipe transition completion to the null position as well. But they don't match up, I guess because the transition completion for the Linear Wipe is a percentage and not an actual position value, per se.

Any thoughts on how to get this to work? Or if it's even possible? I'm sure there is some expression stuff involved that could work for something like this, but hey, I'm not that much of a coder...

Thanks for any insights!

It's only work if you'd rather be doing something else...


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Kevin Camp
Re: Linear wipe completion to Light Sweep centre position...
on Nov 5, 2010 at 3:06:43 pm

something like this should link the light sweep x position to the linear wipe transition percent:

x=linear(effect("Linear Wipe")("Transition Completion"),0,100,0,width);
[x,value[1]]

i assumed a wipe from left to right, if it is right to left, change the last part of the first line from 0,width to width,0.

Kevin Camp
Senior Designer
KCPQ, KMYQ & KRCW


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Roland R. Kahlenberg
Re: Linear wipe completion to Light Sweep centre position...
on Nov 5, 2010 at 3:11:25 pm

I am assuming that you are using CC Light Sweep. When trying to sync two properties with inherently different value systems, the Interpolation Method is what you should be looking at.

Use the following script in CC Light Sweep's Centre property.
//
SweepStart =0;
SweepEnd = width;
LinearTrans = effect("Linear Wipe")("Transition Completion");
linear(LinearTrans,0,100,[SweepStart,width/2],[SweepEnd,width/2])
//

You may want to set opacity keyframes to dissolve on the light sweep effect as the script starts off with the effect at the left of the comp thus, this may create an unwanted flash effect when it first appears.

HTH
RoRK

AE Training in South East Asia. AE templates for sale and rental. Click here for more


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Steve Blacker
Re: Linear wipe completion to Light Sweep centre position...
on Nov 5, 2010 at 4:56:42 pm

Thanks guys, just playing with these now. One thing - Kevin, I got yours to work right away, just the way I need it, but both the linear wipe and light sweep have to be on the same layer. I'm actually trying to make it work so that the linear wipe is on the text layer and the light sweep is on the solid below. I've tried hacking the expression about a bit to get this to work, but I'm not entirely sure how to go about it. Any thoughts?

Thanks so much for your help.

It's only work if you'd rather be doing something else...


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Kevin Camp
Re: Linear wipe completion to Light Sweep centre position...
on Nov 5, 2010 at 5:46:14 pm

this should work. you'll need to direct the "L" variable to the layer that has the wipe effect. you can just select the text between the = and the ; and use the expression pickwhip to select the layer.

L=thisComp.layer('layerthathasiwpeeffectgoeshere'); // this will be the layer that has the wipe effect
x=linear(L.effect("Linear Wipe")("Transition Completion"),0,100,0,width);
[x,value[1]]


Kevin Camp
Senior Designer
KCPQ, KMYQ & KRCW


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Steve Blacker
Re: Linear wipe completion to Light Sweep centre position...
on Nov 5, 2010 at 6:26:28 pm

Thanks very much Kevin - one of these days I'll get my head around expressions...

Have a great weekend!

It's only work if you'd rather be doing something else...


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