Trong thao tác cơ bản Trong các phần trước, tôi đã chỉ cho bạn cách sử dụng các khái niệm cơ bản của hoạt họa các khung hình chính bằng cách sử dụng trong thời gian. Các khung hình chính là rất hạn chế, tuy nhiên. Bạn không thể động bộ lọc hoặc thậm chí vẽ theo thời gian với họ. | Chapter 26 Animating in the Animation Timeline Panel FIGURE 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 disabled 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. 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 time with them. 853 Part VIII Working with Video and Animation FIGURE 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 special 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 champion Rotoscoping tool. Although Rotoscoping involves making time-consuming changes to video frame by frame the effects that are possible are well worth the effort. 854 Chapter 26 Animating in the .
