3D Animation for the Raw Beginner Using Maya

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Chapter 7

A First Look at Adding Animation

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    minimum of about twenty frames per second for the motion

to appear continuous. And in every frame, the models in your scene are potentially

changing their position, shape, color, and other properties.

But digital animation does an almost astonishing amount of work for us. A model can

change in many ways over a series of frames. Recall the three basic primitives: Translate

(move in 3-space), Scale (in three dimensions), and Rotate (in 3-space). When a model is

animated in Maya, these are the three core properties that dene the animation of a model

from frame to frame. We can also animate other properties of an object, like color and

transparency. And yet, we don’t have to tell Maya how to change our scene for every frame.

How does Maya make the task easier? e workhorse of movement in a 3D scene is

interpolation. We can set what are called “keyframes.” Periodically we change the prop-

erties of a model, place it in a frame somewhere on the Maya timeline, and then set a

keyframe. Maya does the rest. It interpolates between keyframes so that models smoothly

change their properties. Maya contains knowledge of how objects interact with each other

in a 3D world, and so we can also program models to be propelled through space and

collide with each other. We have already looked at particles colliding with objects, and

later in this book we will look at multiple solid objects colliding. But right now, we are

only concerned with the process of animating a single model, and we will do this via

keyframing.

Before we look at keyframing we will start with a limited but easy form of animation.

MOVING AN OBJECT ALONG A MOTION PATH

One of the easiest ways to set up movement in a Maya scene is with what is known as

“path” animation. A model can follow a curve drawn through a scene. We can make an

aircra y by overhead and we can even make it bank while doing so. One variation on this

is to animate a camera and to render the scene from the perspective of a camera moving

along a path. is can be breathtaking and even dizzying.

220 ◾ 3D Animation for the Raw Beginner Using Maya

We will move a can of Spam along a path and into the mailbox we built earlier in

Chapter 4. In Figure7.1, we see a photo of a can of Spam, which will be used as a texture.

Figure7.2 shows the scene in wireframe. e mailbox is in the middle. e can of Spam is

in the upper le and close to us, so it looks big. Figure7.3 shows a render of the scene at the

beginning, with the Spam high up and far away.

Creating a Path

In Figure7.4, we select the CV curve tool. We lay down a curve in 3-space in Figure7.5.

e can of Spam is actually that short tubular object above the mailbox; it does not

have its texture or its top and bottom in this image. At this point, we need to decide

how many frames we want to use for the Spam ying into the box. e Timeline is set

to 100 frames.

FIGURE 7.3 e Spam on its way—rendered. FIGURE 7.4 NURBS curve tool.

FIGURE 7.2 Spam scene.FIGURE 7.1 Can of Spam.

A First Look at Adding Animation ◾ 221

Putting an Object on a Path

Now we go to the Animation Main Menu, as seen in Figure7.6. We Shi-select the CV line

and the Spam, then, as seen in Figure7.7, we choose:

Animation Main Menu → Animate → Motion Paths → Attach to Motion Path

FIGURE 7.5 Curve for motion path.

FIGURE 7.6 Selecting the Animation

Main Menu.

FIGURE 7.7 Attach to motion path.