Chapter
10 Animation Basics
Chapter10:
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: â– â–
Create a basic animation using keyframes Create animation using an alternative animation technique
345
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: ■
■
346
■
Describe the process of animation, save and modify keyframes, animate different types of objects efficiently Work with the Track View editor
Chapter 10: Animation Basics
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: ■
■
■
■
■
■
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. 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. 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. Then in the 1920s, Disney combined animation with sound; shortly after, Mickey Mouse was born. His studio also created feature-length animations. Much later, in 1974, computer animation was employed in “Hunger‚” a short computer-graphics (CG) movie. In 1995, Pixar Animation Studios, in collaboration with Disney, created Toy Story, the first fulllength 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
Lesson: Animation Basics
■
347
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.
Front and Left viewports layout
Perspective, Front, and Left viewports layout
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. A key is displayed as a small, colored rectangle. Red is for position, green is for rotation, and blue is for scale.
348
■
Chapter 10: Animation Basics
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. ■
■
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. 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.
Lesson: Animation Basics
■
349
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.
350
â–
Chapter 10: Animation Basics
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.
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.
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.
Trajectory displays the path of the basketball in the viewports. This can be helpful while you animate.
Lesson: Animation Basics
â–
351
8.
9.
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.
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.
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.
352
Drag the time slider to frame 15, and then move the basketball upward so that the trajectory is more like an arc.
■
Chapter 10: Animation Basics
17.
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.
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.
Right-click the basketball and choose Curve Editor from the quad menu. The Track View window appears.
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.
Lesson: Animation Basics
■
353
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.
354
■
Chapter 10: Animation Basics
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.
25.
Once you have changed the keys note how the curve in the Curve Editor window has changed.
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.
27.
Close the Curve Editor, press the P key to change the viewport to Perspective, and then play the animation.
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.
Lesson: Animation Basics
■
355
Summary Having completed this lesson, you can: ■
■
356
■
Describe the process of animation, save and modify keyframes, animate different types of objects efficiently Work with the Track View editor
Chapter 10: Animation Basics
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: â–
Describe alternative animation methods
Lesson: Alternative Animation Methods
â–
357
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. ■
■
■
■
358
■
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. 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. 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. 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.
Chapter 10: Animation Basics
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.
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.
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.
5.
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.
Lesson: Alternative Animation Methods
■
359
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.
14.
Right-click the Front viewport label and switch the view to Camera-Bank.
15.
Similarly, replace the Left view with CameraBlimp 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.
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.
360
â–
Chapter 10: Animation Basics
20.
21.
Make sure you’re at frame 0, and turn on Auto Key mode.
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.
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.
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.
24.
Go to Frame 110. As mentioned earlier, the car is in the middle of the turn (apex) on that frame.
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.
Lesson: Alternative Animation Methods
■
361
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.
362
â–
Chapter 10: Animation Basics
Summary Having completed this lesson, you can: ■
Describe alternative animation methods
Chapter Summary Having completed this chapter, you can: ■ ■
Create a basic animation using keyframes Create animation using an alternative animation technique
Chapter Summary
■
363
364
â–
Chapter 10: Animation Basics