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slider control effect postion key frames

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trev harvey
slider control effect postion key frames
on Mar 19, 2011 at 12:51:56 pm

hi
i've got a 2D layer thats following a fixed path.
and a trapcode stroke layer wiping on a line behind it

i'v fixed the strokes wipe 0% - 100% to a slider and would like to fix the position of the layer to the slider also

can anyone help me out on a little simple expression to do this?

thanks for any help

trev


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Roland R. Kahlenberg
Re: slider control effect postion key frames
on Mar 19, 2011 at 1:02:38 pm

Howzabout linking the layer's Transform.position property to the Point Expressions Control?

HTH
RoRK

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


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trev harvey
Re: slider control effect postion key frames
on Mar 19, 2011 at 1:19:36 pm

hi thanks for the reply,
i'm sort of new to expressions although being using AE seems like forever.

trying to tie the percentage of the 3d stroke completion to the percentage of the entire move of of the layer.

i've got it all working ok the old fashioned 2 sets of keyframes way but sure it can be streamlined better as have many layers doing the same thing at different times

but strugerling to apply your advice sorry to say
no major worries if your pushed for time but is there a idiots guide to do this?


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Roland R. Kahlenberg
Re: slider control effect postion key frames
on Mar 19, 2011 at 1:34:54 pm

Perhaps there is some miscommunication here. I thought that you've already used a slider (an Expressions Control) so linking a layer's position to a Point Control (Expressions Controls) would seem simple enough.

Perhaps you can rephrase your initial issue(s) and I'll see if I can sort things out over on my end.

Cheers
RoRK

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


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trev harvey
Re: slider control effect postion key frames
on Mar 19, 2011 at 2:15:05 pm

sorry RoRK
maybe not explaining it properly will try again.
-on one layer with 3d stroke following a path keyframed from 0 - 100% over 3 seconds for example
-another layer has an object where i'v pasted the same mask data into its position and orientating it along the path. again traverling 3 seconds too

so have 2 sets of keyframes, one for the line, one for the object.

what i'd like is to have both 3d strokes completion % and the position of the other layer tied together via one slider.

the comp is more complex then this but essentially if i can know how to do this i can apply the same logic to the rest of the comp

hope this helps somehow


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Roland R. Kahlenberg
Re: slider control effect postion key frames
on Mar 19, 2011 at 2:55:14 pm

You can link the two 3D strokes End parameter via an Expressions Slider OR simply make one of the 3D Stroke layer a master and the other a follower.

Create an Expression to link the End parameter from the follower layer to the End property of the 'master layer'. Ensure that you remove the keyframe for the 'follower layer's' End property.

Do the same for the position property of the 'follower layer' - ie pick whip its position property to the position property of the 'master layer'.

HTH
RoRK

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


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trev harvey
Re: slider control effect postion key frames
on Mar 19, 2011 at 3:23:53 pm

hi again

thanks for your help, think it seems like its one of those tasks a little tricky to explain without seeing it.

sure you would figure it out in minuets but think its maybe best for this one i stick to things as is as its working ok, just need to keep the comp well oganzied

will do some expression tutorials soon too i think. after 18 years of AE think its about time ; )

thanks again though for your time

trev


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Chris Buttacoli
Re: slider control effect postion key frames
on Mar 19, 2011 at 5:22:48 pm

Trev,
Assuming your slider is ranged from 0 to 100, the stroke parameter can be directly linked via the pick-whip. But the position parameter is going to require the "linear" command.
Now of course, position has two values - x and y - so understand in the expression you will need to define two parameters, one for x and one for y.
So let's say the layer only moves left to right along the x axis from a value of 40 to a value of 600. The y position remains unchanged. You can write this expression for the position.

var amount= [HERE YOU PICK WHIP THE SLIDER CONTROL VALUE];
var x=linear(amount,0,100,40,600);
var y=transform.position[1];
[x,y]


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