Tài iệu Photoshop cs5 by Dayley part 114 pptx

Animating in the Animation Timeline Panel IN THIS CHAPTER Setting and editing keyframes Animating layer properties Rotoscoping Animating DICOM images Animation and keyframes are a big p

Animating in the

Animation (Timeline)

Panel

IN THIS CHAPTER

Setting and editing keyframes Animating layer properties Rotoscoping

Animating DICOM images

Animation and keyframes are a big part of how the Animation

(Timeline) panel works and the effects you can create with your video files Before I show you how to perform basic color correcting and image effects on your video files, I show you how to use the keyframes

in the Animation (Timeline) panel to change your effects over time

Just as you’ve always known since you were a kid, video and animation are

produced by creating a series of images and showing them at such a high

speed that it fools our brains into thinking that we are watching true motion

A standard frame rate to create realistic motion is 30 frames per second

When I was a kid, I always wondered who had to draw and color the

mil-lions of pictures it took to make a full-length animation Now I’ve watched

enough special features titled “The Making of…” to have a pretty good

notion that animators even in the days before computers had many tips and

tricks up their sleeves to make the animating process smooth and efficient

Animating in Photoshop not only employs many of the tips and tricks of

effi-cient animating, it also can automate some of the most tedious tasks We’ve

all seen clay animation productions—the animations created by moving clay

figures a miniscule amount and taking a picture and then repeating the

pro-cess until all the pictures put together create a movie I’ll tell you up front

that some of the animation in Photoshop is going to be just like that,

frame-by-frame animation Not all of it, though, and that’s where keyframes come

into play

A keyframe is one of the essential components of animating in Photoshop A

keyframe allows you to skip many of the tedious steps between “key” points

in your animation In this chapter, I show you what a keyframe is, what it

does, and how you can create and edit it

Creating and Editing Keyframes

So what is a keyframe? When you are creating sequential images for an animation, a keyframe is any frame that defines a turning point in that animation For example, if you want to animate a bouncing ball, the keyframes are the frame where the ball meets the ground and changes direction, and the frame where the ball feels the inevitable pull of gravity to pull it back down All the frames

in between are just continuations of the up or down movement

The in-between frames are sometimes referred to as “inbetweens” or “tweens” for short Creating these frames is called tweening or, in Photoshop terms, interpolating When you create keyframes

in the Photoshop Animation panel, Photoshop has the capability of interpolating the frames between keyframes This provides you as the user with an animation experience that is fun and easy, rather than tedious

A keyframe is indicated in the timeline by a little diamond or square, depending on the interpola-tion setting applied to it The diamond or square is yellow if it is selected or gray if it’s not You can create keyframes in different areas of animation such as position, opacity, style, or global lighting

Creating keyframes

Creating a keyframe in the timeline is a fairly simple process I begin a bouncing ball animation by creating a layer containing a circle over a blank canvas background

You can create a keyframe by following these simple steps:

1 Create a new file in Photoshop

Use the default Photoshop size or larger

2 Use the Ellipse tool found in the Toolbox to draw a circle

Press and hold the Shift key while you are doing it to constrain it to a perfectly circular

shape You can jazz it up by adding a color or layer style I added the Blue Glass (Button) style found in the Styles panel for a quick ball effect

3 Right-click your newly created shape layer to open the pop-up menu, and select

Rasterize Layer.

4 Select Window ➪ Animation to open the Animation (Timeline) panel

5 Click the triangle next to the layer name in the Animation panel to show the layer

properties.

6 Click the Time-Vary Stopwatch next to the word Position to activate it.

7 Make sure the current time indicator is to the beginning of the timeline.

8 Move your object, or selection, through the canvas to the position you want to use

as the start of your animation, as shown in Figure 26.1.

FIGURE 26.1

The ball is ready to drop

9 Drag the current time indicator forward to 1 second.

10 Move your object again

Automatically, a keyframe is created, as shown in Figure 26.2

11 Slide the current time indicator between the keyframes or play back this simple

ani-mation to watch how tweening works.

Now, throwing you into this exercise was like throwing you off the deep end of the pool Don’t worry; I won’t let you sink I just wanted you to get used to the water I covered a few areas that you aren’t familiar with yet, but let’s go over them right now

In Figures 26.3 and 26.4, note the differences in the layer properties listed in the Layers panel as opposed to the Animation (Timeline) panel The Layers panel shows the ball layer just as it would look without the Animation (Timeline) panel open The Animation (Timeline) panel, on the other hand, shows us all new aspects of this layer

FIGURE 26.2

I created a keyframe at the bounce

FIGURE 26.3

The Layers panel is a familiar sight, containing the layers and properties we expect

FIGURE 26.4

The Animation (Timeline) panel shows a whole new array of layer properties

Layer properties Keyframe indicator Time Vary Stopwatch

Keyframe navigators

As you click the triangle next to the layer name, you open a whole new world of possibilities The layer properties that open are different areas where you can create keyframes Anywhere you can create a keyframe, you also can create animation In essence, you can animate in any of the listed layer properties The properties listed in Figure 26.4 allow you to animate in any of the following ways: by changing the position of the layer, by changing the opacity of the layer, by changing the layer style, or by adjusting the global lighting Other possible layer properties exist If my layer contained a mask, for example, I could animate the mask position or the mask enable

The stopwatch next to each of these sublayers is more correctly called the Time-Vary Stopwatch

By default, the Time-Vary Stopwatch is disabled, and keyframes cannot be created Clicking this Time-Vary Stopwatch in each of these layers enables keyframing for that layer

Caution

Disabling the Time-Vary Stopwatch after you have created keyframes deletes them Be very careful that you do

not accidentally disable the Time-Vary Stopwatch and lose all the work you put into creating keyframes n

As you enable the Time-Vary Stopwatch, the keyframe navigators come into view These navigators enable you to jump from one keyframe to the next The direction you jump depends on the arrow you click, of course You can edit the layer properties at existing keyframes as long as the current time indicator is placed directly over the keyframe If the current time indicator is not placed directly over the keyframe, instead of that keyframe being edited, a new keyframe is created This

is an excellent reason to use the keyframe navigators

For instance, in Figure 26.5, I tried to change the drop position of the ball The current time indi-cator wasn’t placed correctly over the keyframe indiindi-cator, so I created a new keyframe When I play this animation back, I end up with a jump in the ball’s position at the end If I had used the keyframe navigator, the current time indicator would be correctly placed to make the edit

FIGURE 26.5

The Animation (Timeline) panel shows a whole new array of layer properties

If you click between the two arrows of the keyframe navigator, you create a new keyframe This isn’t usually the most efficient method, because after you have created it, you need to change the layer property If you change the layer property first, a keyframe is automatically created

Editing keyframes

You can copy, paste, and delete keyframes inside the timeline This is an incredibly useful way to create lots of keyframes in a relatively short amount of time:

1 Select a keyframe by using the keyframe navigator or by placing the current time

indicator over it

A selected keyframe is highlighted in yellow You also can select more than one keyframe

by dragging a selection marquee around the keyframes you want to select or by clicking the Animation (Timeline) panel menu and choosing Select All Keyframes

2 After you’ve selected one or more keyframes, right-click one of them to open the

menu options for the keyframe

You also can find these options in the panel menu

3 Choose Copy Keyframe, and close the menu.

4 Move the current time indicator to the location in the timeline where you want to

place the first keyframe

5 Open the Animation (Timeline) panel menu, and select Paste Keyframe.

As you can see in Figure 26.6, I created a second bounce for the ball I can go on copying and pasting keyframes to continue the bouncing motion

FIGURE 26.6

I copied and pasted the bouncing keyframes to create a second bounce

You can delete a keyframe in the same way, by right-clicking it and choosing Delete Keyframes or

by choosing delete from the panel menu You also can click the Delete button at the bottom of the Animation (Timeline) panel

Caution

The hotkeys (Ctrl/Ô+C, Ctrl/Ô+V, and Ctrl/Ô+X) for copying, pasting, and deleting keyframes don’t work the

way you think they might That’s because in addition to selected keyframes, you have the image layer selected

in the Layers panel If you use the hotkeys, you are copying and pasting in the Layers panel If you are not

care-ful, you could delete the layer you are working on n

You can drag selected keyframes around in the timeline, placing them wherever you want For example, one second is a very slow and ponderous bounce Rather than creating a new keyframe closer to the beginning of the timeline, I can just drag the second keyframe closer to the first

Setting interpolation

Interpolation is defined as the way that Photoshop determines what happens between the key-frames The type of interpolation I’ve demonstrated so far has been Linear interpolation This set-ting is called Linear interpolation because the interpolation creates a path between keyframes That path might be a continuous change of position, or it might be a shadow being gradually created

through time This is commonly called tweening There is a second interpolation setting that doesn’t

create a steady change This interpolation setting is called Hold interpolation When you create a keyframe with a Hold interpolation, Photoshop holds the current status of the layer until the next keyframe, which defines a new status

Linear interpolation

Linear interpolation is the default setting in Photoshop, and you’ve seen how it works After you’ve created keyframes, Photoshop figures out the difference between them and fills in the missing images at the frame rate specified in your file

The shortest distance between two points is a straight line, and Photoshop doesn’t take any other route No matter what you do with the file before creating a second keyframe, Photoshop creates a smooth, mathematically exact transition between the two

I emphasize mathematically exact because when you first try out this method of animation, you find

more keyframes in a movement than you expected I don’t think I’ve ever seen a ball that bounced

at a mathematically exact rate They usually go faster right after hitting the ground, hang in the air

a little and then come down, speeding up as they do That adds at least four keyframes to my bounce

Hold interpolation

Changing keyframes to a Hold interpolation is as easy as right-clicking them and choosing Hold Interpolation from the menu The keyframes selected change to squares rather than diamonds, indicating that the interpolation is set to Hold In Figure 26.7, I changed the keyframes in the posi-tion timeline to Hold interpolaposi-tions Now instead of steadily bouncing, the ball disappears and instantly reappears in a new position at each keyframe

You also can see in Figure 26.7 that not all of the keyframe indicators are diamonds or squares

The second to last keyframe indicator looks like it can’t decide which one it wants to be The dia-mond on the left side of the keyframe indicator shows that the transition coming in is a Linear interpolation The square on the right half indicates that the interpolation going out is set to Hold

FIGURE 26.7

When the position of the ball is set with a hold interpolation, the ball disappears and reappears in a new

location immediately, rather than moving through space to get there

Creating comments

You may have noticed that there is a property at the top of the Animation (Timeline) panel labeled

Comments In this layer, you can place comments on your project The comments are created just

like keyframes First, click the Time-Vary Stopwatch in the comment layer This creates your first comment box Type your comment, and click OK, as shown in Figure 26.8 An indicator is placed inside the comment layer, as shown in Figure 26.9 To create subsequent comments, click between the keyframe navigators You also can open the Animation (Timeline) panel menu and select Edit

Timeline Comment to create a new comment Do not click the Time-Vary Stopwatch again; this

deletes all your comments

To read your comments, hover over the comment indicator until a window pops up, displaying the comment To edit a comment, right-click the indicator and select Edit Comment

FIGURE 26.8

The Edit Timeline Comment dialog box

FIGURE 26.9

A comment indicator looks and acts like a keyframe indicator in the timeline

You can do so much with keyframes, and you can have lots of fun doing it But you may get stopped short trying to use keyframes to animate something they just won’t do, so before I move onto the specifics of animating each layer property, I want to let you know what cannot be ani-mated using keyframes:

l You can’t animate transformations using a keyframe That includes both 2D and 3D

transformations That means no scaling, warping, rotating, or even changing the light set-tings If you change any one of these properties on an object or selection, that property remains constant throughout your animation

l You can’t animate filters using keyframes Although you can convert your layers to

Smart Objects and add Smart Filters to them, giving them their own sublayer, these sub-layers do not have their own property setting in the timeline and cannot be altered over time using keyframes

l You can’t animate any image adjustments Level adjusting and color correction can be

animated by creating a Fill or Adjustment layer and animating its opacity, but you can’t color correct an existing layer over time using keyframes

l You can’t animate the painting tools using keyframes As fun as that would be,

paint-ing over time must be done frame-by-frame within Photoshop