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Volume dial animation - Radial Wipe transition slider for incomplete circle?

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Chris Vo
Volume dial animation - Radial Wipe transition slider for incomplete circle?
on Sep 18, 2014 at 4:30:43 pm

Hi All,

I'm looking to make a volume dial animation that syncs both the rotation of the dial/arrow with the color of the gauge. The gauge is an illustrator file with a Radial Wipe applied.



Any suggestions on the most practical way to control this? I'm trying out using a slider but being a total noob with expressions I'm having the following problems:

1. Converting slider controls 0-100 to rotation degrees for the dial—only 100 degrees of rotation
2. Converting slider controls to % transition complete for Radial Wipe
3. Using an incomplete circle—not a full 360 degrees. Roughly 270 degrees total with starting point at 240.

Any help/suggestions would be greatly appreciated.
(AE CC MAC OS X)

Thanks,

Chris


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Kevin Camp
Re: Volume dial animation - Radial Wipe transition slider for incomplete circle?
on Sep 18, 2014 at 5:29:21 pm

you'd want to use the linear() function to interpolate between the 0-100 scale of the slider and any other scale required for the other properties.

you could use the same expression for each, but change the range of the scales to suit each property:

ctrl = thisComp.layer("Control Null");
start = 0;
end = 240;
amt = ctrl.effect("Slider Control")("Slider");
linear(amt,0,100,start,end)


for the rotation of the dial, set the start and end values to the rotation values of the dial where 'start' would be the angle needed to point at the lowest volume level and end would be the angle needed to point at the highest volume level.

for radial wipe, the start value would be the completion point for the lowest volume level (probably 100) and end would be the completion value at max volume (from the look of your meter, about 33).

Kevin Camp
Art Director
KCPQ, KZJO & KRCW


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Chris Vo
Re: Volume dial animation - Radial Wipe transition slider for incomplete circle?
on Sep 18, 2014 at 8:52:05 pm

Awesome, Kevin thanks so much that worked out perfectly! I have a more challenging idea if you (or anyone) would like to tackle this scenario.

I would like to have the same slider control manipulate a shape/path. Basically its a smiley face where as the volume dial goes up the mouth, "smiles" and conversely as it goes down the mouth makes a sad face. Currently I'm just key framing the middle anchor point on a simple path/shape layer. It works for what I need but it would be awesome if I could sync this up as well. I see the dilemma being the path/anchor "position" doesn't really have a value—I'm open to other ideas to make the smiley face (only mouth needed).

Thanks again,

Chris


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Kevin Camp
Re: Volume dial animation - Radial Wipe transition slider for incomplete circle?
on Sep 18, 2014 at 9:09:34 pm

you could use a very similar expression using the linear() function to interpolate time between the mask path keyframes,

try something like this (the expression assumes you have just two keyframes)

ctrl = thisComp.layer("Control Null");
sad = key(1).time;
happy = key(2).time;
amt = ctrl.effect("Slider Control")("Slider");
t = linear(amt,0,100,sad,happy);
valueAtTime(t)


if the happy face is the first keyframe simply change the value in the parentheses to the correct key index -- ie, happy = key(2).time would change to happy = key(1),time.

Kevin Camp
Art Director
KCPQ, KZJO & KRCW


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Chris Vo
Re: Volume dial animation - Radial Wipe transition slider for incomplete circle?
on Sep 18, 2014 at 9:46:25 pm

Worked...obviously this is child's play for you thanks so much for your help, Kevin!


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