Tài iệu Photoshop cs5 by Dayley part 117 doc

Creating a new video layerThe first thing you want to do to start animating frame by frame in the Animation Timeline panel is to create a new video layer.. Only video layers contain the

FIGURE 26.21

To begin animating text, add the text and choose a starting position for it

You also can use the Mask Enable animation property to turn masks on or off in an animation

This property works only with a Hold interpolation In other words, the mask is enabled or dis-abled, never halfway in between

Tip

Because the Mask Enable property cannot contain Linear interpolation, you can’t dissolve a mask in or out

You can create the same effect, however, by creating two layers The first contains the unmasked area and the

second contains the previously masked area (no mask would be needed in this case) Then you could animate

the opacity of the second layer n

Rotoscoping Basics

In the previous sections, I showed you how to employ the basics of animating using keyframes in the timeline Keyframes are very limiting, however You can’t animate filters or even paint over

FIGURE 26.22

Animating the warp and position of text can add life to an animation

You can animate just about anything, however, by employing the technique of Rotoscoping

Rotoscoping has been around almost as long as movies themselves It entails tracing animated characters or scenes over live action film It’s a very useful tool in aiding animators to create more realistic movement because they are copying that movement from life It’s also used to create

spe-cial effects, such as the light sabers in the Star Wars films.

Today, with the use of computers, Rotoscoping has taken on a broader definition Now when you hear the term, it can mean any painting or editing of a video frame, whether or not that frame is over a live action scene With its powerful painting capabilities and filters, Photoshop is the cham-pion Rotoscoping tool

Although Rotoscoping involves making time-consuming changes to video frame by frame, the effects that are possible are well worth the effort

Creating a new video layer

The first thing you want to do to start animating frame by frame in the Animation (Timeline) panel is to create a new video layer Only video layers contain the Altered Video layer that can be changed frame by frame, so if your document doesn’t already contain a video file, you need to do this in order to animate changes at all Even if you already have video layers in your document, you want to create a new video layer in which to store changes In fact, it’s a good idea to create a new layer for each major element in your animation

Creating a new video layer is as simple as choosing Layer ➪ Video Layers ➪ New Blank Video Layer A new video layer is added to your project

Tip

The first thing you want to do with a blank video layer is give it a unique name that’s descriptive of the element

on that layer n

A video layer has one additional property to other types of layers in the Animation (Timeline) panel That property, as you can see in Figure 26.23, is an Altered Video sublayer Within that sublayer, frames can be altered one at a time to create an animation

Creating modified frames

Now that you have a new blank video layer, you are ready to animate You can animate frame by frame in the timeline by creating modified frames inside of the blank video layer I show you how this is done

You can create individual frames inside any video layer by following these steps:

1 With the blank video layer highlighted, move the current time indicator in the

time-line to the position where you want to make the first change

2 Paint or otherwise make changes to the layer.

3 Click the triangle next to the name of your blank video layer

This shows you the properties of that layer, including the Altered Video sublayer Within

the Altered Video sublayer, a small segment has appeared, indicating an altered frame, as shown in Figure 26.24

4 To build onto the changes you have already made, choose Layer ➪ Video

Layers ➪ Duplicate Frame to move to the next frame and duplicate the frame you just created

5 Make further changes to your animation.

Continue duplicating frames and making changes to your animation until you have completed it, as shown in Figure 26.25.

FIGURE 26.23

Animation can be created on a new blank video layer with the Altered Video property

You may not want to build on the animation created in a previous frame That’s okay; just navigate

to an unaltered frame and make new changes You can move to the next frame by using the frame advance in the playback controls or by selecting Go to Next Frame in the Timeline panel menu

You also can choose Layer ➪ Video Layers ➪ Insert Blank Frame

Tip

You may have noticed that there are no shortcuts for the menu-intensive task that I just had you complete

When you are duplicating frames as often as building animation requires, you get pretty tired of constantly

navigating through the menu to do it Bet you’d like to create a shortcut, right? Choose Edit ➪ Keyboard

Shortcuts, and you can create your very own shortcuts for the actions that you perform most frequently

Now your only worry is actually finding an unused shortcut! n

The purple segment in the Altered Video line indicates one altered frame.

Utilizing onion skins

An onion skin, a real onion skin right off of an onion, is semitransparent and very thin Onion skin paper is also semitransparent and thin—that’s how it got its name This quality has made it ideal for using in animation to make the transitions smoother from one frame to the next The idea is that the previous frame can be traced onto the next frame, making the small changes necessary to create movement

Computer animation has made using onion skins an incredibly simple process By temporarily making your animation frames semitransparent, you can create the next step in your animation by referring to the last one

FIGURE 26.25

By animating these stars frame-by-frame, they appeared a little at a time in the night sky

That’s the basic idea Photoshop allows you to set parameters for the Onion Skins that go way beyond just being able to see the last frame from the present frame Besides having multiple set-tings for the Onion Skins themselves, there are other benefits of using Photoshop You can create Onion Skins in any layer and make modifications in a different layer For example, you might want

to animate a motion trail for something that is moving in a video layer, a space ship maybe You could create Onion Skins in the live action video layer and paint over the motion in a blank video layer

Onion Skin settings

To access the Onion Skin settings, select Onion Skin settings from the Animation (Timeline) panel menu The Onion Skin Options dialog box opens, and you can set any number of ways for your Onion Skins to work As you make changes in the dialog box, you can see how they affect the view

of the current frame in the timeline in real time, as shown in Figure 26.26

The Onion Skin Options have a much greater range of options than a piece of tracing paper.

l Onion Skin Count: You can set the number of frames that you want to show through to

the current frame, both before and after the current frame You can show up to eight frames before and eight after

l Frame Spacing: This determines whether the frames being shown are consecutive or

appear with gaps in between A setting of 1 means the frames are shown in consecutive order A frame setting of 2 means that only every other frame is shown

l Max and Min Opacity: If you have more than one Onion Skin count, you probably want

to see the closer frames at a higher opacity than those that are farther out from the current frame These two settings allow you to set the maximum opacity for the closer frames and the minimum opacity for the farthest frames The frames in the middle are a setting some-where in between the two opacities

l Blending Mode: The blending mode changes the way that the opacity setting is applied to

the Onion Skins Different files are easier to work with in different blending modes You can choose from four blend modes in the Onion Skin Options: Normal, Multiply, Screen, and Difference

When you have made the changes to the Onion Skin Options, click OK to close the dialog box

The Onion Skins are automatically enabled with the setting you specified You can toggle the Onion Skins on and off by using the Onion Skin icon at the bottom of the Animation panel

As you move along in your animation, the Onion Skins move with you, helping you to create any frame along the timeline You can change the settings at any time as your needs change

Restoring frames

As you make changes to various frames, you might come to a point where you want to discard the edits to one frame or all of them This is as easy as selecting the frame you want to restore to its original look and choosing Layer ➪ Video Layers ➪ Restore Frame If you want to discard all the altered frames, choose Layer ➪ Video Layers ➪ Restore All Frames Unfortunately, this process is not as easy as using the hotkey for deletion or dropping the Altered Layers into the trash, but hopefully you won’t need to use it often

Animating DICOM Files

A DICOM file is a medical image or series of images created when you have a sonogram, a CT scan, an MRI, or any number of procedures that take an image of the inside of your body

Photoshop has the capability to view these files as well as animate them Animating a DICOM file

is very similar to importing an image sequence Of course, to create an animation, you must have a series of DICOM images

To open a series of DICOM files and animate them, follow these steps:

2 Browse to a DICOM file that is a series of images

DICOM files have the capability of saving an image sequence as one file Select the file, and click OK A dialog box opens, allowing you to set the parameters for opening the DICOM file, as shown in Figure 26.27

3 Select the frames you want to animate by holding the Ctrl/Ô key as you select them

one by one, or click Select All

4 Select Import Frames as Layers from the options on the right side of the dialog box

to create a layer for each frame that is imported.

5 Select Anonymize if you want to scrub out the headers contained in the DICOM

images.

7 From the Animation (Timeline) panel menu, select Make Frames from Layers

You can open a DICOM file in several ways, or you can simply export it to a jpg In this example, you

want to animate it, so we need to create a layer for each image in the DICOM file

You can see in Figure 26.28 that a frame has been created for each image contained in the DICOM file Now you can view the file as an animation or export it as a video file format

FIGURE 26.28

The Animation (Frames) panel shows more clearly how each image has become a frame in this new

DICOM animation

Summary

In this chapter, you learned how keyframes play an important part in making animation easy and fun With the powerful Photoshop tools at your disposal in creating animations, what you can cre-ate is limited only by your imagination You learned how to do these things:

l Create and edit a keyframe

l Animate the different properties of a layer

l Animate text warp

l Animate one frame at a time

l Animate DICOM files