No. 151, Using the Z Axis

Most of you, except those who have never worked in or experimented with a 3D application such as Maya or 3D Studio Max, will know what the Z axis is. Whereas the X axis indicates movement to left and right, or side to side; and the Y axis is up and down, or top to bottom, the Z axis is front to back, moving toward or away from the camera.  (Or the virtual camera itself may be moving along one or more of these axes.)

Here's a little graphic I created in Autodesk Sketchbook. The 3 axes are
usually coded with these colors in onscreen graphics.                                   

Defining movement on screen in this way is precise and convenient when working in 3D, but we can use the same language in describing the drawn movement of objects and characters in our 2D world.
Foreshortening of an arm or leg is a way of working in the Z axis because it implies that something in the drawing is extending out or back from the plane in which the character "exists." If you enlarge the foot on the foreshortened leg, you are emphasizing even more the existence of the Z axis--of the depth of the space your drawings depict.

I once did some animation of two pigs--big, cartoon hogs, actually--dancing in a circle on a small table that eventually collapses from their weight. This was part of a TV ad for the Oregon State Fair. It was funny and pretty effective, and everyone seemed to like it, but now when I look at the drawings I see where I could have made better use of the Z axis.

My original dancing pigs.

And how I might do them today, with a little more depth to the drawing.

Well, you can never go back and redo animation after it is broadcast. It is what it is, for all time.
But you can learn to look out for opportunities to improve as you work on new things.

I just finished a new scene for my film Carry On. My Old Man character, having in the previous scene (as seen in post No. 149) managed to get his legs out of a taxi and become prepared to stand up in the street, is now seen in closeup as his head and shoulders rise into the frame and he looks about.

After a hold as he looks off to the right (his left), he turns and looks back the other way. To begin the turn and bring him out of the hold pose, I naturally wanted some kind of anticipation. Instead of having him swing to the right before going left, I have him mostly pulling back from the camera, then coming forward again as he changes direction.

Drawing 47 is the hold drawing before he turns to look the other way.

Drawing 91, the extreme for the anticipation.

Drawing 115, the final hold drawing.

This is deliberately utilizing the Z axis, and I think you will agree, it makes an effective anticipation. Since the Renaissance, artists working on flat, two-dimensional surfaces have known how to suggest depth in their drawings and paintings. Animators should be mindful of these possibilities too.