Although 3D technology is very impressive and is looking less and less “stiff” with the improvement of GUI 3D software, I prefer 2D’s flexibility, energy and relation to drawings, as well as the mental exercise and joy of translating a thought into a moving drawing. I may not end up with a perfect object rotation in 2D, but with practice it’s possible to complete an animation much faster in 2D and there are subtle things being communicated in (and via) the 2D illustrations of a movement.

For this rotation example, I want to share my thoughts about how you can turn your brain into a computerized movement of outlines that a 3D program might do more perfectly but less interestingly.

Let’s start with the concept that we are rotating on a single axis and we have placed our
“camera” on two drawings we’ve made. Our eye serves as the camera and the trapezoid represents our eye looking slightly down upon the edge of a circular point and path of rotation.


Left Profile

This allows us to start with just two simple drawings we’d want to make anyway when making an animator’s “turn around”. The basic “trick” I want to impart/teach to you is the idea that by simply averaging the difference between two lines, you can end up with the proper “in between” state (or “tween”).

While you are holding in your head the principle “draw the average line” you should also bear in mind “my ‘turn around’ might be subtly changing on more than one axis.” You might not have perfectly rendered a 90-degree rotation, because when you were looking on the object ‘straight on’ you wanted a better peek and you tilted it up or down or slightly to a side. Unlike perfectionist animators (and I don’t want to irritate any clean up artists but) I think you should just run with it for the purposes of a sketch and for the purposes of learning your own process. I find that while concentrating on all the other things, you might pay attention to your own process and figure out the best starting places and what you could improve on, little by little.

One improvement in thinking I’ve made is to see the perfect average between the profile and front drawings as different from a 45-degree rotation. The average isn’t exactly the middle. As you can see from these compasses, a 45-degree rotation will move the ‘nose’ of our character much closer to a full 90-degree rotation appearance. When we draw the average, we are actually drawing something like 1/3 of a 90-degree turn.

The “tween” we want to draw can be placed about 1/3 of the way along the timeline. An actual 45-degree rotation of the object, the true “average” between a front or back and a profile, appears to our eye/camera closer to the profile extreme.

So now we are drawing while thinking:
1. Draw the average line
2. Our first drawings might not be perfect but we’re going with it
3. Minor corrections can be made later, including moving and adding frames to flesh out missing areas

Thanks to digital animation tools like the Future Splash/Flash/Animate versions, we have tools that simulate and “improve” on light table functions (though staring at a computer screen for hours has its down sides too; remember to take breaks every couple hours! Eat carrots! Get Omega-3s too!).

Let’s create a blank middle frame between the two “extremes” (front and profile) we made, turn on “Onion Skinning” (the button shown in the lower left as it appears in Flash), and look at that previous frame and one frame ahead with the faded outlines that the effect gives us.

The concept of our “character” is an abstracted animal shape mask. Between the two first “extremes” we can see that the front of our character’s mask can be averaged roughly with a middle drawing of the edge.

We can also do the same for its opposite eye, and now we’ve built up some simple reference to complete the rest of the drawing.

When faced with complex shapes at awkward angles, concentrate on finding the “exact middle” of the difference by imagining (or even sketching) a line showing how the point in question must move from point A to point B. Then, on such a scale, you can find your point A-B. As shown.

As you become better at “eyeballing” you can choose a point that isn’t exactly 50% along the way. You might, for example, imagine in your mind’s eye a 4th principle: the flattened circle and where the object is along that rotation. Are we at the 1/3 of 90-degrees? Unlike computer-generated animation, there are no rules for how to keep things conforming to your cartoon world. Simply organize your thoughts how you wish and “scrub” the timeline (flipping simulated pages) to see if you want to change the drawing. A more accurate “path” would not be the straight lines I’ve drawn here but a subtle curve as if we are tracing our fingers along the edge of a circle.

You might look at or keep something simple around you for reference, such as a bowl, to hold a point on the edge with your finger and then observe the edge from different angles to watch how the mind organizes thoughts. You can rotate your hand and look at it from different angles then apply similar rotations to a given object. You can apply that to as many angles as you want until you find something you want to change, then take new observations. Life can be observed afresh while animating (one more perk of 2D is that it can keep things light, airy, directly observed, and leaves out heavy computer middle processes). Don’t worry about how your perception may be different from someone else’s. The joy of animating is observing while learning how you observe and sharing that with the world. As you gain perspectives from seeing/hearing/learning how others perceive (any kind of art or human activity gives insight about this, really) you can find yourself observing your observation of other people’s observations! Oh my goodness. This is all too much for a brief tutorial.

Now, I’ve drawn the rest of the shape — which is the top of the “lip” of the character — by finding similar “middle points”.

As you increase the number of drawings (I like to do the two “tweens” of the 45-degree drawing, then the four tweens between those, and finally the eight tweens between those) you find that finding the average points becomes increasingly simple once you’ve hammered out those extremes. (This is why I suggest you just jump into it. If you worry too much about making perfect extremes at the start, you won’t get a chance to learn more from your animation techniques as you draw the tweens.)

You may notice that the “third way” between these overlaid frames is almost done. The dotted line indicates the most obvious way to sketch the tween of the line describing the back of the mask. Can you see other the other elements that have been “averaged”?

When you’ve completed the number of different drawings, you can turn on the “view all frames” mode and see if your half-rotation is looking like a good arc or if it’s a bit wobbly. As you can see, our character doesn’t turn in a perfect circle. Switching between this view and single frames allows you to modify frames to fit within a fancy circle rotation.

If you are lucky enough to have an object you want rotated symmetrically, you only need to make half the frames plus one extra (such as the “back”), then graphically flip them. Now we have a good “under drawing” sketch and basis for animating this character at various angles along a certain “view”. Already you can see some funny ‘quirks’ about this sketch, though you get an idea of what’s going on.

To complete the drawings may take many more hours, but by bravely facing your perceptions and wrestling them to a 2D surface, you may find yourself exploring some of the joys of animation. Thanks for reading!