merry-go-round

[Filip Vandueren]

do want to actually draw the motion path they’ll all follow ?
Or can it be done with a formula: like a sinusoidal up and down along a circle ?

[Aldigi]

Whichever way works. I would suppose frawing a path would be simpler.

[Steve Roberts]

How about making each object go up and down, then arranging them all in a circle, creating a rotating null in the center, then parenting them all to that null?

[Michael Szalapski]

Steve’s right – a null is the way to go.

Here’s how I would do it:
Make them 3d layers
Position them back in z space half the width you want the carousel to be.
Animate the up and down motion (every other one up while every other one goes down…or something, you might not want the up and down motion at all.)
Create your null and make it 3d.
Parent one layer to the Null
Rotate the null 180 degrees
Parent another layer to the null
Rotate the null 90 degrees. You should now have two layers moved, one on the left, one on the right.
Parent another layer to the null
Rotate the null 180 degrees
Parent another layer to the null
Rotate the null 45 degrees
Parent another layer to the null
Rotate the null 90 degrees
Parent another layer to the null
Rotate the null 90 degrees
Parent another layer to the null
Rotate the null 90 degrees
Parent your last layer to the null.

Now, when you animate your null’s rotation, all of your layers should be evenly spaced and moving in a circle. You can set them to auto-orient towards the camera if you want.

That’s one way anyway…

– The Great Szalam
(The ‘Great’ stands for ‘Not So Great)

No trees were harmed in the creation of this message, but several thousand electrons were mildly inconvenienced.

[Filip Vandueren]

The problem with just animating the up/down motion is that it’s very difficult to sync everything together with the rotation like a merry-go round would:

each “horsey” goes up at the exact same position, even if it slows down or speeds up: they still go up at that position.

here’s a solution with expressions:

FreeVideoCoding.com

basically it uses the Y rotation of the parent null to calculate a sinusoidal up down in the Anchorpoint.

the Null has controls for:
“wobbles per revolution”, “amplitude”, “merry-go round radius”, and “N

[Rutger]

I recently wanted a similar animation, I just wanted to have images rotating in a circle around the camera and I approached it using expressions. Instead of having the images move in a circle, I have the camera move instead, so this may not help you. But maybe you can give the following a shot and see if it works and maybe you can adapt it. I also set up expression sliders so that the expressions should work for almost any number of images or videos, but I will explain it using real numbers for now.

Create a comp and create a null (3d) and a camera. Parent the camera to the null.
Now set the position of both camera and null to [0,0,0]

Now load all your image or video files, making sure that they are 3d layers and that they are layers 1 to 8. Then enter the following expression into the position property of your images:

yAmp = 500;
Radius =1000;
x = Radius*Math.sin(Math.PI*2*(index)/8)
y = yAmp*Math.sin(time-index);
z = Radius*Math.cos(Math.PI*2*(index)/8);
[x,y,z]

Then in the Yrotation property enter the following
(index)*360/8

Copy the position and rotation expression to all 8 image layers.

Now, for the expression of your null enter the following in its Yrotation property:

rotationspeedpersecond = 0.1;
360*rotationspeedpersecond*time

Obviously by playing with these numbers you can create different effects, just having to change and copy and paste them gets pretty tedious though.
So, in my project I have set up sliders (Effect>Expression Controls> Slider Controls) and this way I have control over the number of images (the number 8 in all expressions), the radius of the circle (Radius in expressions) and the amplitude by which the images move (yAmp), and you can go on and on…

I hope this works for you.

Rutger