QuickTime Sprites

Introduction

Sprites in QuickTime have been around for a while. But now that there are several products that support sprites, it's much easier to create your own sprite movies. To find out what a sprite it, what products you can use to create them, and one or two things you probably didn't know you can do with sprite tracks, read on.

If you've got QuickTime 3 installed and want to see some examples of sprite movies, go to the Sprite Sample Page .

What is a Sprite?

A sprite is like a character in a movie. It can move, change appearance and interact with other characters in the movie. If you've used Macromedia's authoring tool, Director, then a sprite is similar to a castmember in that program.

QuickTime stores the information about each sprite in one or more sprite tracks. As the movie plays, QuickTime uses the information in the sprite track to draw the sprites. They are not prerendered - a sprite can respond to user input, and you can use Movie Player to enable/disable sprite tracks and change the way they are drawn. You can even replace the contents of a sprite with another track.

Why should I use Sprites?

Sprites are useful in many cases:

• For many kinds of animations, a QuickTime sprite track provides a much more compact representation of the animation than a traditional "pre-rendered" video track.
• The sprite track will have better performance characteristics across a wider range of machines. If you create a sprite movie, it will play back on any machine with QuickTime 3 installed.
• There are cool ways that QT sprites can interact with each other. Some sprites are actually just filters that modify the appearance of other sprites. Other sprites draw themselves semi-transparently on top of other sprites. Sprites can react to external events as well.

Creating QuickTime Sprite Movies

Currently there are several tools that we are aware of that allow you to create and save QuickTime sprite movies:

Director 5.0 or greater from Macromedia with the QuickTime Sprite Movie Exporter XTRA (Currently Macintosh-only).

You can use Director 5.0 or greater to create your animation in Macromedia Director 5 and then use the QuickTime Sprite Movie Exporter from Apple to convert the cast members to sprites. You can download the Sprite Exporter from the QuickTime home page . For more information on the QuickTime Sprite Movie Exporter, see "Using the QuickTime Sprite Movie Exporter" .

Object Dancer from Paceworks (Macintosh only)

Object Dancer is a powerful animation tool that lets you control all attributes of each object you are animating, including animation path, rotation, skew, color, size and transparency. When you save your animation as a QuickTime sprite movie, each object is converted to a sprite.

Lightning Draw/Web from Lari Software (Macintosh only)

Lightning Draw/Web is an illustration product for creating scalable, reusable vector graphics that can be optimized for the web as QuickTime 3 vector media. Lightning Draw/Web graphics can also be used in Object Dancer to produce QuickTime 3 sprite animations.

WebPainter from Totally Hip Software (Macintosh only)

This cell-based animation tool enables anyone, novice to professional, to create QuickTime 3 sprite animations.

Digital Box Office and WebBurst from Power Production Software .

WebBurst is a tool that creates interactive Java applets without programming. Digital Box Office is a tool for CD-ROM authoring.

Note: Support for creating sprites is currently limited to the Macintosh because until QuickTime 3, sprites were not supported under Windows. Look for Windows-based sprite editing tools in the near future.

Using Chapter Headings

The QuickTime Sprite Exporter for Macromedia Director is one of the few tools that lets you create a Chapter Track. If you add markers to the Score, the Sprite Exporter will convert them to a text track and they will show up in the Chapter Heading section of the movie controller.

Movie Player lets you look at the Chapter track via the Get Info dialog for the sprite track:

The Chapter section in Movie Player's Get Info Dialog

If the text track for the sprites is the first (or only) text track with a Chapter list reference, the markers can be viewed in the Chapter Headings area of the movie controller. Clicking on the Chapter headings displays a popup of all the markers (see below), allowing the user to easily jump from one section to the next.

The Chapter Headings popup for the Transparency demo

The chapter headings are really just a text track, as you will see if you choose Enable tracks... from the Edit menu in Movie Player and enable the text track.

Image Overrides

By default, sprites exported from Director with the Sprite Exporter are static images - one per castmember in the Director movie. Movie Player allows you to override one or more sprites with other tracks in the movie - for example, a video track. For instance, by overriding the QuickTime logo sprite in the transparency demo with a video track, the video will play where the logo is and the other sprites will continue to work seamlessly - the bubble and glass will render themselves properly on top of the video sprite, etc.

Transparent bubble over QuickTime logo

To accomplish this, first you need to add a video track to the movie. This is done by opening a video movie, selecting the entire movie, copying it to the clipboard, returning to the sprite movie, selecting all of the sprite movie, then holding down the Option key while you pull down the Edit menu and choosing Add.

Once you've added the video track, select the sprite track in the Get Info dialog (see below). Select the sprite you want to override with video and click the Select Override Track button. Choose the video track from the dialog that is displayed.

Once you've selected the video track as the override track, it replaces the sprite area. All the usual effects of other sprites on top of the video sprite still work (see below). Thus, if you have a ripple sprite on top the video sprite, the video will ripple as it plays.

The QuickTime logo overriden by a video track - bubble is still transparent

You can turn off the override other by choosing (none) in the Select Override track dialog, or by disabling the video track in the Enable tracks... dialog. The second method is more convenient if you have a lot of sprites using the same override track and you want to turn them all off or on at once.

Top of Page