Expression for Making Something Travel in an Oval?

[Mark Walczak]

Hey everyone,

I was wondering if someone could point me in the right direction to creating an expression that would cause a layer to move in a 2D oval path. I have exhausted such options as pasting an oval mask into the position of said layer, but it really doesn’t give me the control I want. Essentially, my dream expression would have:
– X-radius width adjustments
– Y-radius height adjustments
– a link to a slider control where I can control the revolutions from zero to 1,2, etc.

Any ideas? Let me know if I need to clarify…

PS – I also tried Andrew Kramer’s 3D Orbit tool, but it only supports circles, not ovals…

What makes you explode?
http://www.explosivegraffix.com

[Dan Ebberts]

Try this, with slider control “a” for the radius in the x direction, slider control “b” for the radius in the y direction, and an angle control:

a = effect(“a”)(“Slider”);
b = effect(“b”)(“Slider”);
angle = effect(“Angle Control”)(“Angle”);

center = [thisComp.width,thisComp.height]/2;
rads = degreesToRadians(angle);
center + [a*Math.sin(rads),b*Math.cos(rads)]

Dan

[Mark Walczak]

Dan,

I believe I’ve said it before, but I’ll say it again: YOU ARE AMAZING!!!

Thank you so much – you’ve saved me a precious hour of messing around with Java. I hope to learn it more in-depth soon!

Best,

What makes you explode?
http://www.explosivegraffix.com