Circular Motion Expression?

[Xinlai Ni]

radius = yourRadius;
startAngle = degreesToRadians(yourStartAngle); // yourStartAngle in degrees
T = yourTimeToCompleteOneRevolution; // in seconds
angularSpeed = 2 * 3.1415926 / T;
xt = yourCenterX + radius * Math.cos(angularSpeed * time + startAngle);
yt = yourCenterY + radius * Math.sin(angularSpeed * time + startAngle);
[xt, yt]


Xinlai Ni
Software Engineer, Google Inc.

[Ryan Hill]

I think also you can use Math.PI instead of 3.1415…

Plus, if you’re not up on your trigonometry, there’s plenty of ways you could rig this up by parenting one layer to another layer and then using .toWorld() to get the position of it.