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Draw parametric equations in AE, how to make them do deformation animation ?

Taku Wilson
December 2, 2021 at 12:39 pmHello, I want to use the expression of ae to simulate the rose curve in mathematics. I applied a mathematical formula to the position attribute, and I can draw rose curves with different parameters.
However, I want to change the threeleaf curve into a fourleaf curve or another mathematical formula curve. I don’t know how to use expressions to make such an animation.

Kevin Camp
December 2, 2021 at 10:42 pmIf you use the Writeon effect and apply this expression to the Brush Position property it will draw a rose curve with a set number of petals:
r = 5 ; // rate in seconds
n = 3 ; // number of petals
a = 300 ; // size
t = time * Math.PI + r ;
n2 = n / Math.abs( ( ( n % 2 )  2 ) ) ;
x = a * Math.sin( n2 * t ) * Math.cos( t ) ;
y = a * Math.sin( n2 * t ) * Math.sin( t ) ;
value + [ x, y ]Adjust the r, n and a as needed.
In my testing it works pretty well, except for 6 petals, which for some reason only produces 3 petals…

Kevin Camp
December 2, 2021 at 11:03 pmI botched the rate… this should fix it:
r = 1 ; // rate to draw each petal in seconds
n = 4 ; // number of petals
a = 300 ; // size
n2 = n / Math.abs( ( ( n % 2 )  2 ) ) ;
t = time * 2 * Math.PI / n2 / 2 / r ;
x = a * Math.sin( n2 * t ) * Math.cos( t ) ;
y = a * Math.sin( n2 * t ) * Math.sin( t ) ;
value + [ x, y ]

Taku Wilson
December 3, 2021 at 7:12 amI know write on, it can only make an object do a curve movement, I want to make a curve into another curve. thanks

Taku Wilson
December 3, 2021 at 7:24 amI want to animate the transition of different curves by changing r n a slider

Taku Wilson
December 3, 2021 at 7:30 am 
Taku Wilson
December 3, 2021 at 7:35 am 
Filip Vandueren
December 10, 2021 at 11:42 amFor most values of the rose curve you would need infinite amount of points before the curve lines up again. Do you want to limit it to a maximum number of rotations ?
like here: https://www.youtube.com/watch?v=PDrfcPgnhSA
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Filip Vandueren
December 10, 2021 at 1:26 pmHere’s my project that does it with a shape instead of writeon:

Taku Wilson
December 10, 2021 at 3:22 pmThanks, I found that the for loop is calculated every frame, which is very interesting!
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