| **Revert value to zero once to comp edge**
on Mar 18, 2018 at 5:33:55 am Last Edited By Jim Johnston on Mar 18, 2018 at 5:38:11 am |

Hey all. I have a position expression which moves in a certain direction each frame as follows (thanks to Dan Ebberts).

`spd = effect("Slider Control")("Slider");`

angle = effect("Angle Control")("Angle");

d = spd*(time-inPoint);

r = degreesToRadians(angle);

x = d*Math.cos(r);

y = d*Math.sin(r);

value + [x,y]

But I need the x and y values to reset to 0 once they reach a certain threshold (such as the comp width/height).

I tried adding `if(x>100) x=0;`

which works but keeps the value of x at 0 for the remainder..

Something really simple I suspect but not getting anywhere at the moment!

| **Re: Revert value to zero once to comp edge** on Mar 18, 2018 at 6:11:36 am |

Figured it out. AE doesnt store variables over time apparently. So a modulus function works instead just fine I think

`spd = effect("Slider Control")("Slider");`

angle = effect("Angle Control")("Angle");

d = spd*(time-inPoint);

r = degreesToRadians(angle);

x = d*Math.cos(r);

y = d*Math.sin(r);

value + [x%1280,y%720]