3dFOA - Pendulum

This assignment will account for 16% of your final grade. Hand-in will be due at the start of class 7


The Pendulum. (PM) Modules 4-6. Use the Swinging Pendulum Rig and animate it across the screen with 3 starts and stops, 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. 6 sec. long. (144fr)

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

Watch these great tutorials by Keith Lango on overlap and follow-through:

Tutorial 1Tutorial 2 and Tutorial 3


Are you ready? Here we go:

Step 1) 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.


Step 2 ) Animate the root of the Pendulum. 


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:


Step 3) Animate overlap on segment 1.


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.

Step 4) 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. 

Step 5) Animate the second 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.

Step 6) 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. 










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 visualisation tool is going to be critical to getting this working well.

Good Luck!