# Animating a Ferris Wheel

I'm new at blender and I'm trying to animate a ferris wheel. But blender is still very difficult for me and I'm stuck. I made the base and the little cars separately but I have no idea how to let them rotate properly.

Anyone who wants to explain me how to do that?

Many thanks!

Firstly, make sure the 'cars' are separate objects, and make sure the wheel's Object Origin is at the centre of the wheel.

Here, you can see I have a circle, with monkeys (as separate, selectable objects) arranged around the outside:

The Object Origin (the orange dot in the centre) of the wheel means the wheel will rotate around the centre. The Object Origin of the monkeys ('cars') are at their top so they will rotate around this point as if they are 'hanging'.

Now, you want to select all the 'cars' then select the wheel last and press Ctrl+P to parent the cars to the wheel. Rotating the wheel will make all the cars rotate with it, but obviously they will not 'hang' like a real 'car' would.

For this we can add a Constraint to lock the rotation of the 'cars'. Select one of the cars and in the Constraints tab of the Properties editor add a Limit Rotation constraint :

By looking at the axis of the 'car' I can see it is the red x axis that I want to lock the rotation of:

On the constraint you just added tick the Limit X checkbox and also For Transform. By leaving the Min and Max values for the x axis on the constraint at '0' I am making sure the 'cars' can rotate 0 degrees.

Select all the cars and then select the car that you just added a constraint to and go to Object> Constraints> Copy Constraints to Selected Objects in the 3D View header:

This copies the constraint to all the 'cars'. Now if you rotate the wheel the 'cars' will follow but their rotation will be locked:

Now you are free to animate the rotation of the wheel and let the constraints manage the 'cars'.

• Thank you so much for the helpful explanation! It works! – Lukas Boon May 9 '18 at 13:57
• You won't have the cars positioned properly. The object origin for the cars needs to be slightly lower than the object origin of the frame of the ferris wheel. Each car's center of gravity is below the frame. You want the cars to look like they are hanging down within the frame (see OP's picture) not centered on the frame. – Keeta May 9 '18 at 15:47
• @Keeta Thank you. I have updated the instructions and imagery to reflect this. – Ray Mairlot May 9 '18 at 16:20

Animation Nodes can be used as an easier parameterized solution. The parametric equation of the circle can be used to define the location of the objects. And since we are not editing the rotation of the object, the objects' orientation is maintained.

Now, we can set the start value to a multiple of time, resulting in a phase shift in the trigonometric functions and subsequently rotation animation. The multiple $30$ controles the speed of rotation.

• Well I think the other answer is more correct for this particular problem because a ferris wheel has certain attachment points to consider (and you might eventuall want to use physics for the cars also), I had completely forgotten or missed that animation nodes even existed so the example is appreciated. – StarWeaver May 9 '18 at 22:05

Another approach using Dupliverts (memory efficency of instances as bonus).

Duplicating on vertices allows instances to maintain their global orientation in confront to dupliface. So we will use this feature.

Prepare Driving wheel:

1. Add Plane or Cube, switch to Edit mode
2. Select all vertices and hit Alt+M -> Collapse. This will merge all geometry into one vertex
3. In Edit mode, translate this vertex from origin point along one axis only (for example X of Front View). Just make sure distance between vertex and origin point has to be same as actual Wheel's radius
4. Switch cursor pivot type to 3D. Go back to Object mode and put 3D cursor in origin point, switch to Edit mode once again, select all and hit Ctrl+H -> Hook to new object. It's important to get Hook to be created strictly in place of origin point (or center of rotation), so watch carefully for it
5. Add Screw modifier. This will create circle shape mesh from our single vertex.

Prepare Car:

1. Simply parent Car object to our Driving wheel object.

Animation itself:

1. Enable Duplivert option in Driving wheel settings (Object tab->Duplication->Verts). Now you should get a full circle of Car's instances
2. Animate Hook rotation on Y if looking from Front View. All Cars now should follow Hook's rotation

NOTE: To edit number of Cars go to Driving wheel's Screw modifier and change number of steps, more steps -> more vertices -> more duplicated Cars. Don't forget to synchronize viewport and final render step number to get correct results.