Pendulum (PM)

This assignment can be challenging. Try not to break anything.

Please refer to FOL for grade value and due date.

The Pendulum (PM)
Use the Pendulum Rig provided and animate it across the screen with 3 starts and stops, with one being a reversal of direction. There must also be a change in elevation. Play-blast from an orthographic side view. Featured principles: Slow In/Out, Overlap/Follow Through, and Pose to Pose/Straight Ahead. The scene must be exactly 6 sec. long. (144fr)

What I'll be grading on this assignment:
  • Do you meet all of the assignment parameters?
  • Does the pendulum consistently convey it's physical properties?
  • Do you meet all the required parameters of the assignment?
  • Is there a clear and convincing sense of mass?
  • Are you effectively using the principles of Timing, Slow In/Out, Arcs, and Overlap and Follow Through?

Hand-in file parameters:
  • Movie file type must be either .MOV or .MP4
  • either H.264 or MPEG4 compression
  • 960 x 540 resolution
  • File size must be less than 50 MB
  • No .zip or .rar files please
  • File must be named as follows:

       <Your last name>_<Your first name>_<assignment_code>.<file type>


To start, watch these great tutorials by Keith Lango on overlap and follow-through:

Tutorial 1Tutorial 2 and Tutorial 3

Value Operators

These are handy little math functions that you can use anywhere is Maya that you have a field with numbers in it. (eg. The graph editor, the channel box)

Some handy ones are:

+=1  This adds 1 to the value - enter this in the time field of the graph editor to shift keys 1 frame later in time. 
*=-1 (*) means multiply. This will multiply the value by -1, essentially inverting it (I use this later in the tutorial)
*=.6 Multiply the value so that it is 60% of it's original amount. Good for toning down movement in the Graph editor. *=1.5 would increase the movement to 150% of it's original amount.


Next: you'll want to learn more about BhGhost, a fantastic tool for Maya created by Brian Horgan
 (watch more about it here:

Make sure you download and install the latest version. 
You can get it here at:

Are you excited? Let's give it a try!

Module 5 -  Start with a Clear Plan and Work in Layers

With the grading criteria in front of me, I sketch out a drawing of what I'm going to do for this assignment. As you can see; it doesn't need to be a great drawing, Just something to help me quickly make decisions and keep on track with the assignment. I use the following plan for the example: you will need to come up with a different plan of your own.

Here's my first pass, just animating on the root of the pendulum. I need to work out the timing and mechanics on the root before I can work out the follow through, so I haven't touched the tail yet.

Here's what I have at the end of the first pass:

A fun trick - let's stabilize the tail of my pendulum so that it stays hanging straight down. I do this by copying the RotY curve on my main controller, which looks like this:

And I copy it to RotY of the first controller of the pendulum tail. Then I select the entire RotY curve on  CNTRL 1 and use this little command   *=-1    in the value field to invert it. I end up with something that looks like this:

The selected curve is the original, the other was inverted by using a value operator: *=-1 (times equals negative 1)

Now the tail of my pendulum perfectly counter animates against the movement of the base. Like this:

Make sure you're happy with the movement of the base before you work on tail overlap.

Next Step - Animate overlap on just the first tail segment

I'm going to work on animating just the first segment of the pendulum tail, and hide the lower parts. I'll use the tool bhGhost to help me see clearly how to animate the tail.

I'll make sure I have strokes turned on in my cameras show menu. Using bhGhost, I'll be able to smooth out the spacing on my first tail segment, making sure that the tip Ease Out of each acceleration like this:

Note how the spacing on the end starts slow, easing out from the beginning of the action.

I also want to have the tail Follow Through on the hard stops, and Ease In to the apex of the swing at the end. Like this:

The larges spacing will be at the bottom of the swing, where gravity is helping to accelerate the action.

As I'm working, I focus on 2 ideas:

1. Inertia. The tail of the pendulum resists change. It will always try to do whatever it was doing in the previous frame. If it was sitting still, it will try to stay sitting still. If it was in motion, it will try to keep going the same speed, in the same direction. 

2. Gravity. I also pay attention to the idea that gravity is constantly pulling the pendulum to a straight down position. In some cases, this will cause the tail to speed up as it tries to return it's default position. If no energy is added by movement from the top, the tail of the pendulum will swing back and forth, losing energy each swing, until it comes to a rest hanging straight down again.

When I've finished, I have something that looks like this:

Here is what the animation curve looks like on the first tail control:

A smooth curve doesn't mean smooth movement - the tail is inheriting rotation from the root.

Be sure you have this much progress to show for next class.


Module 6 - Dailies

Get ready for feedback in the next class. If there are any issues with the first segment of the tail it will cause problems with the animation of the rest of the tail segments. Based on the feedback, make any necessary fixes to the first tail segment. 

Next Step - Animate the second tail segment

When you've got the first part of the tail work on the next segment of the tail, using the same workflow. Here's what I had at the end of that process:

Here are the curves for both segments of the tail. The lighter curve is the first segment, the darker one is the second segment:

Note how the second tail segment curve is delayed relative to the first segment? That is a big part of overlapping action: some parts of the character trail behind other parts. When I finish the third tail segment, you'll see that it trails behind even more in the graph editor.


Module 7 - Finish with the last segment of the tail

Now I animate the last part of the tail using the same workflow as the first two parts. Here's what I end up with:

Here are what the RotZ curves of all three tail segments look like. This animation looks a bit too active and lively. I may scale some of the actions down a bit to make it feel more like the tail is just lifeless drapery with no motive power of it's own.

I've used Edit>Change Curve Color in the graph editor to make this easier to see. 

No happy with the results: Here are some troubleshooting tips

Is your pendulum too 'springy'? 

Does your pendulum tail feel spring loaded? Here are a couple of fixes to try:

Add amplitude:
Try having the pendulum tail swing through further on the other side of the swing
Add frames:
If it moves too quick back to vertical, it definitely makes the tail feel like it's spring loaded. Try slowing it down by adding frames.

Is your pendulum too 'floaty'?

Does the tail of your pendulum feel like it's made of silk drapery, blown by the slightest breeze?

Fewer frames at the extreme of the swing so that the tail returns to vertical faster and it will feel like air resistance has less effect.
Don't hold the tail back for too long as the base of the pendulum moves side to side. The tail will hold back for just a few frames, but then it will try to return to vertical by overshooting and recovering.

That's the entire process! Hopefully you will end up with a nice example of Overlap and Follow Through using this step by step workflow. bhGhost or a similar visualization tool is going to be critical to getting this working well.

Good Luck!

- Dave