Post on 26-Mar-2016
description
345
Chapter
10
Animation BasicsChapter 10:
In this chapter, you will learn the essentials of animation. Although animation is not always used
in presentations of design projects, it is a good idea to have some familiarity with its concepts and
capabilities. More in-depth explanations of this topic would be reserved for more advanced
material.
Objectives
After completing this chapter, you will be able to:
n Create a basic animation using keyframes
n Create animation using an alternative animation technique
346 n Chapter 10: Animation Basics
Lesson: Animation Basics
Overview
3ds Max® and 3ds Max Design provides tools for animation, but to animate well, you also need to
understand and use the laws that govern animation. In this lesson, you will learn about the general
principles of animation and the tools provided for in the software.
Objectives
After completing this lesson, you will be able to:
n Describe the process of animation, save and modify keyframes, animate different types of
objects efficiently
n Work with the Track View editor
Lesson: Animation Basics n 347
Animation Theory
About Animation
Before you start animating objects in the scene, there are some fundamentals rules to learn about. We
will start with some background information on animation and then move into the specifics.
History of Animation
People have always told stories. Animation, like filmmaking in general, is one way of telling a story. But
what is animation exactly? Animation is a sequence of images, with slight differences from one image
to the next, which gives the impression of movement.
Here are some key developments in the history of animation:
n In 1826, one of the first animation gadgets was the thaumatrope. It consisted of a disc with an
image painted on each side: a bird and a cage. You would crank it using a string, and when you
released the disc it would spin, and the bird would appear to be inside the cage.
n Later, in 1874, Eadweard Muybridge was hired by a California governor to see whether or not a
trotting horse ever had all four feet off the ground. The California governor needed the proof to
settle a bet. Muybridge, with a series of photographs, proved that a trotting horse does indeed
have all four hooves off the ground at a certain time. His photographic sequences were one of the
origins of motion pictures.
n In 1913, Felix the Cat was one of the first animated cartoons to hit the big screen, and by far one
of the most popular of its time.
n Then in the 1920s, Disney combined animation with sound; shortly after, Mickey Mouse was born.
His studio also created feature-length animations.
n Much later, in 1974, computer animation was employed in “Hunger‚” a short computer-graphics
(CG) movie.
n In 1995, Pixar Animation Studios, in collaboration with Disney, created Toy Story, the first full-
length CG movie.
Today, 3D animation has taken the place of traditional, hand-drawn animation as a cheaper, faster,
and more efficient way of animating characters, with specialized television cartoons broadcasting
around the clock, along with the movie and gaming industries, 3D animation seems to be the
way to go.
The basic principles of animation remain the same, where slight differences in object position from
frame to frame create the illusion of motion.
A bouncing ball is a classic animation exercise
348 n Chapter 10: Animation Basics
2D versus 3D Animation
3D animation differs from its elder sibling in that you have to deal with three dimensions instead of
two. When you animate, you have to consider all angles in order to have a good understanding of your
animation. Thus, the viewport configuration becomes very important.
You need to know where the positions of the limbs are going to be at all times, so they don’t intersect
with one another.
Time
Time is the essence of animation. When you move your hand to pick up a coffee cup, you need time
to reach your goal. If the allocated on-screen time is too slow or too fast, it changes the whole meaning
of the motion. Thus, time is a crucial element of animation.
In animation, the measure of time is a unit called a frame. More precisely, the measure of time is
defined by the number of frames in a second of animation. Depending on your medium or
geographical location, one second of animation can be equal to 24 frames (film), 30 frames (the North
American NTSC video standard) or 25 frames (the European PAL video standard). A second is still a
constant measure of time, but the difference is the number of images that are shown in one second.
By default, 3ds Max and 3ds Max Design are set to work in NTSC mode at 30 frames per second
or 30 fps.
Time is also very important in making your animation look right. This is called timing!
Keyframing
In the early days of traditional animation, an artist would hand-draw all the images of a movie, from
start to finish. Later on, the task would be divided among several artists. The lead animator would draw
the main positions of a character, or the “key” positions, and assistants would draw the in-between
frames.
In 3D animation, the term “key” is still in use and is sometimes referred to as a keyframe. It is a value
recorded on an object at a specific frame.
Front and Left viewports layout Perspective, Front, and Left viewports layout
A key is displayed as a small, colored rectangle.
Red is for position, green is for rotation, and
blue is for scale.
Lesson: Animation Basics n 349
Once you’ve created keyframes, the software acts as your assistant and creates the in-between frames
by interpolating automatically from key to key.
Auto Key & Set Key
There are two distinct types of animation approaches: automatic keying called Auto Key and explicit
keying called Set Key. Each approach has its own particular advantages.
n Auto Key allows you to animate freely. When Auto Key is on and you are on a frame other than 0,
keys are created automatically when you transform an object or change its parameters.
n Set Key creates animation only when you explicitly set an animation key. This method of animation
favors what is often referred to as pose-to-pose animation. You establish all the transforms and
parameters you need at a given frame and then set the keyframe.
Animation Control
As you have just seen, it is easy to animate objects. However, it is crucial that you are also able to
control how objects behave when animated. The application offers many tools to control the
animation so that it does not get out of hand. There are also some tools to help you embellish the
motion so you can achieve more realistic results.
Track View
Track View is a very important feature; it’s the animator’s special tool for fixing and adjusting
animation. There are two types of Track View: the Curve Editor and the Dope Sheet. The Curve Editor
is useful for correcting the trajectory of an animated object and to adjust timing, while the Dope Sheet
is more useful for copying and pasting keys.
Timing
Timing is arguably the most important aspect of animation. Timing is the number of frames it takes to
make a certain movement or the time it takes to hold that movement.
Take a really energetic character, almost too energetic. Picture him in your head, the way he walks,
moves, talks. All motion emanating from this character is going to be really fast and snappy.
Now picture an old, weary character. The same brisk walk would be impossible for him to achieve.
On such a character, the timing should be slow—really, really slow—like walking on the moon.
350 n Chapter 10: Animation Basics
Ease In / Ease Out
The principle of ease in/ease out is also known as cushioning. It is the art of accelerating and
decelerating an object, so its motion does not look too mechanical.
For example, a bouncing ball slows down before it reaches its peak in midair, and then accelerates as
it begins to descend.
Arcs
There is almost no uniform linear motion in real life. Almost everything moves in some sort of curved
motion. Arcs are important for the esthetics of movement. In particular, the joints of people and
animals work like hinges, and cause our limbs to describe arcs as they move.
For example, even when motion is linear in real life, as when a heavy object falls, there is almost always
some acceleration.
Lesson: Animation Basics n 351
Exercise: The Bouncing Ball
1. Open the file Basketball_Start.max.
2. On the main toolbar, click the Select
Object button, click the basketball in any
viewport to select it.
3. Near the bottom of the application window,
click the Auto Key button.
The border of the active viewport turns red
and so does the timeline. This is a reminder to
let you know that you’re now in record mode.
When you make a change to the scene, such
as transforming an object or adjusting a
numeric parameter, the change is recorded
and used for animation.
4. Move the time slider by dragging it to the
right until you reach frame 30.
5. Activate the Front viewport and maximize the
view by pressing ALT+W.
6. Select the basketball, then right-click it and
choose Properties from the quad menu.
7. In the Display Properties group, turn on
Trajectory and click OK.
Trajectory displays the path of the basketball
in the viewports. This can be helpful while you
animate.
352 n Chapter 10: Animation Basics
8. On the main toolbar, click the Select
And Move button. In the Front viewport,
move the ball to a point above the hoop, as
shown in the illustration below.
9. Drag the time slider back and forth. The
basketball is now moving in a straight line. On
the track bar just below the viewport, notice
the two red rectangles: these are the keys that
recorded the ball’s movement. In the
viewport, the straight red line shows the ball’s
trajectory.
NOTE: The trajectory is a red line with white dots.
Each white dot represents a frame. A white box
around a dot represents a keyframe.
10. Drag the time slider to frame 15, and then
move the basketball upward so that the
trajectory is more like an arc.
11. Go to frame 45, and move the basketball so it’s
just touching the floor, as shown in the
illustration.
12. Next, you’ll create the bouncing effect on the
floor. Go to frame 55 and move the ball
slightly up and to the left, and then go to
frame 65 and move the ball down to the floor
and slightly more to the left. This takes care of
the first bounce.
13. Repeat the procedure to create additional
bounces, each new one smaller than the
previous one. Create a bounce at frames 73
and 80 (up and down), frame 86 and 92, and
then finish the sequence with a small straight
line between Frames 92 and 100. Use the
following illustration as a reference.
Lesson: Animation Basics n 353
14. Turn off Auto Key mode.
15. Play the animation. The animation looks
a little loose. Default interpolation sometimes
results in animation that is overly smooth and
looks artificial. You’ll be adjusting this.
16. Right-click the basketball and choose Curve
Editor from the quad menu. The Track View
window appears.
17. Reposition the Track View window, so you can
also see the action in the viewport.
You’ll be using the Track View - Curve Editor to
ensure that when the basketball hits the panel
or the floor, it appears to bounce off these
surfaces, instead of the soft, unrealistic
motion it’s following currently.
On the left side of the Curve Editor window is
the controller window. The controller window
lists objects (and other entities) in the scene,
along with their motion tracks and any
controllers that have been assigned. A
controller is a module in 3ds Max that controls
animation.
On the right of the Curve Editor window are
function curves. These show the motion of the
basketball in three axes: red for X, green for Y,
and blue for Z. The first key you need to
change is the X-Position key at frame 30.
This is where the ball hits the backboard.
18. In the Curve Editor, in the controller window
you will see the three position tracks for the
basketball. Resize the window to your liking
using the lower left corner of the window. The
two icons at the lower left will zoom extents
the timeline.
354 n Chapter 10: Animation Basics
19. Then click the X-Position track so that it’s the
only one highlighted in yellow. In the function
curve window, only the red curve should
appear.
20. In the Curve Editor, click the key at the top of
the curve (at frame 30) to select it. Two
tangent handles appear on the key.
21. Hold down the SHIFT key on the keyboard,
and drag the handle on the left side, bringing
it down until it points directly to the key at
frame 15.
By moving the tangent, you create a break in
the continuity of the movement. Now the ball
bounces off the backboard more rapidly,
creating a sharper movement.
22. Drag the handle on the right side until it
points at key 45. The trajectory at frame 30
now looks like an inverted “V” shape.
23. Play the animation.
24. Next, you need to fix the bounces off the floor.
In the Curve Editor’s controller window, click
the Z Position track. Now a blue function
curve appears, representing the Z axis
motion.
Lesson: Animation Basics n 355
25. You’ll have to fix the frames when there is
contact with the floor. You can try a different
method this time to create a “V” shape in the
trajectory. Hold down the CTRL KEY and click
the keys at frames 45, 65, 80 and 92. These
keys represent the position of the ball as it hits
the floor.
HINT: Selecting keys in Track View works like
selecting objects in a viewport. Clicking a key
selects it. CTRL+click adds or removes keys from
a selection, and ALT+click removes keys from a
selection. You can also drag a rectangular
region to select multiple keys at once.
26. In Track View, on the main toolbar of the
Curve Editor, change the type of tangent
to Fast.
Once you have changed the keys note how
the curve in the Curve Editor window has
changed.
27. Close the Curve Editor, press the P key to
change the viewport to Perspective, and then
play the animation.
356 n Chapter 10: Animation Basics
Summary
Having completed this lesson, you can:
n Describe the process of animation, save and modify keyframes, animate different types
of objects efficiently
n Work with the Track View editor
Lesson: Alternative Animation Methods n 357
Lesson: Alternative Animation Methods
Overview
There are several different methodologies for creating animation, keyframing is only one of them.
In this lesson you will learn about some alternative methods.
Objective
After completing this lesson, you will be able to:
n Describe alternative animation methods
358 n Chapter 10: Animation Basics
Alternative Animation Methods
Typically, the animation you create through keyframing is created with Bezier animation controllers.
Animation does not always have to be created though keyframes. The software provides alternative
methods using constraints and other controller types. Constraints are animation devices where one
object’s animation will be partially or totally controlled by another object. A controller is an animation
device where a parametric algorithm controls the animation of the object.
n Path constraint – Animates an object to follow a spline. You can use path constraint to animate a
car driving down a road, or a roller coaster car to follow the roller coaster track.
n LookAt constraint – Controls an object’s orientation based on the position of another object in
the scene. For example, you can use the LookAt constraint when you want a character’s eyes to
follow the movement of another person or object in the scene.
n Noise controller – Adds irregular motion to an object. Noise can be added to the motion of a car
along a rough terrain to provide the effect of driving along a bumpy surface.
n Waveform controller – Adds a smooth rhythmic motion to an object’s transforms or parameters.
It can be used to slowly turn on a light, and then slowly turn it off several times, or for something
to pulse rapidly on an increasing scale.
Lesson: Alternative Animation Methods n 359
Exercise: Driving Around: Using Path Constraint
In this exercise, you’ll use the path constraint
method to animate a car moving along a racetrack.
1. Open the file Path_Start.max.
The scene shows a racetrack and a race car.
There are also two spline objects running
along the inside and outside edges of the
racetrack you’ll use to control the car motion.
The animation length has been set to 600
frames. You need about 20 seconds for a lap
around this circuit.
2. Select the car body in the front view.
3. In the Animation pull-down menu, choose
Constraints > Path Constraint.
4. In the Top viewport, move the cursor to the
inner edge of the racetrack. A rubberband line
appears to show you are constraining the car
to the spline.
5. Click on the inner spline (InLine) to reposition
the car to the start of the inner spline.
6. In the Command Panel, make sure
you’re in the Motion Tab.
7. At the bottom of the panel, in the Path
Parameters rollout, click the Add Path button.
8. Click the outer edge of the race track
(OutLine) to add it as a second controller path.
The car is now positioned in the middle of the
racetrack.
360 n Chapter 10: Animation Basics
9. Scrub the animation slider bar, notice that the
car is traveling backwards.
10. Go to frame 150 and notice that the car does
not rotate as it follows the turn.
11. In the Path Options area of the Path
Parameters rollout, click the Follow checkbox,
so that the car points in the direction of travel.
12. Enable the Flip option so that the nose of the
car points forward.
13. Play back the animation.
The car follows the racetrack and remains in
the middle at all times. The animation looks
fine at this point but it still needs some
adjustments.
14. Right-click the Front viewport label and
switch the view to Camera-Bank.
15. Similarly, replace the Left view with Camera-
Blimp and the Perspective view with
Camera-Track.
16. Set the three camera views in shaded
mode (F3).
17. Select the car in any view, right-click it and
choose Object Properties from the quad
menu.
18. In the dialog that appears, turn on Trajectory.
This makes it easier to see the line the car is
following.
19. Click OK to exit the dialog. Next you’ll animate
the weights of the inner and outer control
splines to have the car follow the ideal
race line.
Lesson: Alternative Animation Methods n 361
20. Make sure you’re at frame 0, and turn on Auto
Key mode.
21. In the Motion panel, highlight the OutLine
path and set its weight to 100. This will make
the car run closer to the outside edge of the
track.
22. Go to frame 50. The car is just about to
negotiate the long left turn, and at this time,
should be even closer to the outside wall.
23. Set the InLine weight to 15 and the OutLine
weight to 100.
24. Go to frame 110.
The car is now in the middle of the turn and
should be as close as possible to the inner line.
In racing terminology, this is called the apex.
25. Set the InLine weight to 100 and the OutLine
weight to 20.
26. Continue creating weight keyframes using
the following table as a guideline:
27. Play back the animation. The car is now
following the ideal racing line.
28. Go to frame 125.
The car is in the middle of the first turn. Notice
the problem: The car doesn’t bank to follow
the topology of the turn. It remains level
throughout the animation.
29. Go to Frame 110. As mentioned earlier, the car
is in the middle of the turn (apex) on that
frame.
362 n Chapter 10: Animation Basics
30. In the Motion panel, turn on the Bank option
and set Bank Amount to 10.0.
31. Scrub the animation.
Notice the bank amount is animated to go
from values 0 to 10 between frames 0 and 110.
However, you only want the car to bank as it
enters the turn (on frame 50) and not before.
32. Go to frame 50 and set the bank amount to 0.
33. Go to frame 200 and set the bank amount to 0
again to level the car out of the turn.
34. Scrub the animation to test the banking. The
car now behaves properly in the first turn.
35. Repeat the procedure for turn three, setting
the banking amount to 10 in the middle of the
turn (frame 480), and zero out the banking
amount on frames 410 and 550.
NOTE: Turn two is shallow and does not require
any banking.
36. Turn Auto Key mode off and play back the
animation.
You can open the file Path_Final.max to view
the finished animation.
Chapter Summary n 363
Summary
Having completed this lesson, you can:
n Describe alternative animation methods
Chapter Summary
Having completed this chapter, you can:
n Create a basic animation using keyframes
n Create animation using an alternative animation technique
364 n Chapter 10: Animation Basics