Animation Assignment #11
Double Arm Swing

Successive Breaking of Joints 4a
Everyone has two arms, so we need to animate the other arm for this cycle.

For this assignment you are to animate the opposing arm from the Single Arm Swing assignment. The arm should look the same as the one you just completed. Animate the arm from the shoulder to the fingertips.

We need to match the action of the second arm to the exact same action as the first one.

Purpose and Principles Involved
We're working out the action of the arm swing so that we can move on to the more complicated walk cycle. This assignment is different from all the other ones, in that you can't just flip the drawings over and trace them off to get the oposing arm. We have to think three dimensionally here. The opposing arm is actually a mirror image of the one you just did. Because of this we need to work out the perspective for the arms. We'll get to that in just a minute.

The principles involved are all the same as before.

Thought Process
You've already gone through the entire process of acting out the action of the arm swing. If you were a "normal" person, you would have gone through the action using both of your arms while walking. Whatever you did with your left arm, you would have done the same thing with your right arm. If you didn't, it would have been an uneven, non-symmetrical action which only works if your character has a weird non-symmetrical walk or a limp.

Let's start with drawing #1. This is the right arm in it's back-most position.

Now we take drawing #9 (the other key pose) and lay it over top of drawing #1. This is the same arm in the forward most position. In this case, it's across the front of the body as well. (I've made drawing #1 fainter as though you were looking at it on your own light table.)

Place a blank sheet of paper over top of these and using the drawing #1 as reference, draw the left arm in the "mirror position".

Start by creating a vanishing point off to the right side of the page around the shoulder level. We need to do this in order to properly plot the perspective of the arms so they look three dimensional.

Up to this point, all your animation has been pretty much 2 dimensional, meaning that it doesn't break the picture plane and come toward or away from you the viewer on the animation paper. In this assignment, we're breaking the picture plane to create a feeling of three dimensionalism. As the right arm rotates across the body, it moves back, away from us in space. To continue with this illusion, we need to understand the perspective point that we will be working with. That's why we have the vanishing point.

So, we're drawing the mirror image of arm #1 here using the perspective lines. We don't really need drawing #9 unless you're actually going to draw the arm on this sheet. I'm only suggesting a separate sheet of paper because it might help you keep the arms straight in your head as you continue on.

The other option would be to draw the left arms in red. I'll proceed with this demonstration that way. (Remember, the red hands are drawn on a separate sheet of paper from this point on. Don't draw them on the same page as the right arms!!)

So, you can see here how I've drawn in the left arm in red as a mirror image to drawing #1. The hand is rotated slightly so I can see more of the palm of the hand. You really need to think the positions through on this assignment.

In the Seaweed assignment, it was all about line control and volume control. In this assignment it's about mind control. Keeping track of what it is that you're drawing all the time. If something goes weird in the animation, it's because you lost control and were not thinking about what was supposed to be happening.

Now do arm #9 the same way. (Remember, these are on a separate sheet of paper.)

Continue this same process with the breakdowns #5 and 13.

Then you do the same thing you did with the single arm swing, go back and do all the inbetweens. When you have all the left arms completed, take the drawings from your single arm swing assignment and trace off each of the corresponding arms that you just finished in red. Be sure the arm is in the opposite position: 1 goes with the red #9, 9 goes with the red #1.

1-9, 2-10, 3-11, 4-12, 5-13, 6-14, 7-15, 8-16, 9-1, 10-2, 11-3, 12-4, 13-5, 14-6, 15-7, and 16- 8.

So, your final #1 should look like this:

#5 should look like this:

#9 should look like this:

And #13 should look like this:


Take a peek at the pencil tests

Here is the single arm version.

And this is the double arm version color coded so you can follow them easier.

You have to think this through. If you don't, you won't be able to complete it. Once you've done it, it'll make sense. This is a pretty complicated arm swing. Maybe try something a bit easier first.

Here's a slightly more simple swing.

You can watch my lecture for this assignment on my YouTube channel:

Part 1 of 3
Part 2 of 3
Part 3 of 3

Use the inbetweening flipping method shown in this video.

Pencil Test
At this point, because things are getting complicated, it would be best for you to shoot a pencil test. This will also help you to see if the timing is proper.

Watch a short video showing how to flip your final animation stack.

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