by Brad Smith Using Sprite Tracks & LiveStage Pro April 20th, 2001 Sprites are the backbones of many interactive QuickTime movies. Sprite tracks hold within them these important items. If you didn't check out the last column, I have included my brief summary of sprite tracks below. Sprite Track: A sprite track is a visual track. It stores samples that are displayed on the screen to the user. Sprites can be interactive in many ways. They can be used to play sounds upon a mouse click, they could jump to another point in the movie, they could assign a value to a variable, or start/stop playback of a video. They are also capable of animation. In fact, the things sprites can do are almost infinite. In order to more adequately understand sprite tracks and their usage, I will now go into more detail. A sprite track, like any other type of track, is a container for a certain type of content. Within this container individual samples can be placed. In LiveStage Professional, samples are placed on a timeline in a window containing the track lists, thus indicating at what times certain events will occur or certain items will be displayed. Sprite tracks, naturally, accept sprite samples. These samples are broken down further into individual pieces, called sprites. To review, sprite tracks contain sprite samples, which in turn contain individual sprites. Got it? You may be saying, "Okay, sure. I see the progression. That leaves just one thing unanswered: “What, exactly, is a sprite?” The analogy that is most often used is that sprites are like actors on a stage. In LiveStage Professional, the stage is the area where you can adjust the positioning of items and preview the appearance of your movie. More specifically, the stage for a sprite is the boundaries of the sprite track within your movie. Like in a theatrical production, sprites can dance around the sprite track, change costumes, and even interact with the audience. At different points within the movie, a sprite's properties can be modified to change either it's appearance, location, or both. Animation created by LiveStage Professional of a sprite within a sprite track is quite different than traditional video-based animation. Each sprite is assigned an image that it shows when displayed on the screen. Animation of this sprite occurs in realtime on the machine that is playing the movie. In other words, all the data the movie contains is the image, or images, assigned to the sprite and information on when, where, and how that sprite will move or be altered on the end user's screen. QuickTime then takes over and displays the movie based on the information it is reading. Sprite animation significantly decreases the file sizes of movies, therefore making this sort of animation perfect for distribution over the Internet to both broadband and low-bandwidth users. Here are three great examples of sprite animation and user interactivity: Cruise Line Puzzle iMac Match Game Bricks Sprites and sprite tracks can also be used to create interactive navigation menus for web sites. Once again, small file sizes make this possible. File size, however, is not the only advantage of using QuickTime for navigation menus. As indicated in my previous columns, QuickTime and sprites can be used as replacements for JavaScripted and Java applets on Web pages. I encourage you to explore the possibilities of sprites on the LiveStage Developer Network. I have only touched the surface of what's possible. Everyday someone is doing something with QuickTime and sprites that hasn't been done before. It is, truly, an amazing part of an amazing technology. iResources Ars Technica Mac OS X 10.0 Review - John Siracusa takes a very in-depth look at Mac OS X, it’s performance, stability, and applications. He touches briefly on QuickTime 5.0, but overall this is a good read for anyone interested in Mac OS X. MacInTouch: 2001 Streaming Media Market Report - Dale Sorenson examines the streaming media market from his unique perspective and knowledge, covering QuickTime, Real Media, and Windows Media Player. He tends to blur the line between streaming media and traditional downloaded media, as well as ignores the interactive capabilities of QuickTime. Overall, this is a great source for information on the current state of QuickTime in the marketplace. You are encouraged to send me your comments, or to post them below. Most Recent iQT Columns Using Sprite Tracks & LiveStage Pro April 20th Understanding Components In QuickTime March 30th Enhancing The QuickTime Web Experience March 23rd iQT Archives Back to The Mac Observer For More Mac News! Brad Smith is currently attending school in Lincoln, Nebraska, and has used Macintosh computers since 1984. Brad is a member of the National Association of Photoshop Professionals, and an interactive media devotee, by hobby. In middle school, Brad and three other students from Lincoln, NE, were recipients of the ISTE MultiMedia Mania international multi-media contest in the middle school division. You'll typically find Brad going all out on a simple twenty-point school project by making an interactive QuickTime movie in LiveStage Professional. In other words, he has no life! Brad has three brothers and is a big fan of the Dave Matthews Band. His enjoyment for music is evident in the vast collection of CDs he possesses and the fact that music is required to do any sort of work on the computer. He welcomes your comments at brad@macobserver.com.