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Looping a sine expression within a 10 sec animation

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Nina Frost
Looping a sine expression within a 10 sec animation
on Jul 12, 2018 at 6:08:53 am

Hi All,

I am trying to loop a sine expression within a 10sec frame so that when playback the sine wave is seamless.
What i did was this

Create a layer under Trapcode Particular
under Emitter>Position XY the expression is

xPos = 2800;
freq=0.15;
amp=random(50,100);
y = amp*Math.sin(freq*time*Math.PI*2);
yPos = y+360;
[xPos,yPos]

See my sample here.





Need some guidance on how to write the sine expression to loop whilst holding the same wave height/length and frequency ?

Please help!


Thanks!
Nina

xPos = 2800;
freq=0.15;
amp=random(50,100);
y = amp*Math.sin(freq*time*Math.PI*2);
yPos = y+360;
[xPos,yPos]


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Dan Ebberts
Re: Looping a sine expression within a 10 sec animation
on Jul 12, 2018 at 6:15:04 am

Since your frequency is 0.15, after 10 seconds it will have completed 1.5 cycles, which won't loop correctly. It would work if your frequency were 0.1 or 0.2, but I don't know if either of those will work for you.

Dan



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Nina Frost
Re: Looping a sine expression within a 10 sec animation
on Jul 12, 2018 at 6:31:20 am

Thanks Dan,

I have amended the expression to the following

xPos = 2800;
freq=0.1;
amp=random(50,100)
y = amp*Math.sin(freq*time*Math.PI*2);
yPos = y+360;
[xPos,yPos]

However it seems that there's still a tinee misalignment with the particles.

Please see attached.






I checked my other settings and think i have accurately set all other keyframes to loop at the same value start and end.





Can u assist to correct me where i went wrong?

Thanks!
Nina

xPos = 2800;
freq=0.1;
amp=random(50,100)
y = amp*Math.sin(freq*time*Math.PI*2);
yPos = y+360;
[xPos,yPos]


Return to posts index

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