Working with Scenes & Tracks

Scenes are the content of a movie. A movie can have many scenes, and scenes are played in the order they appear in the scenes property of a movie object.

Creating a new Scene

To create a new scene call the sdl.Scene constructor:

var scene = new sdl.Scene();

Adding Scenes to and Accessing Scenes in a Movie

The Movie object contains an array of scenes in an property called scenes. The scenes are played in the order they appear in that array. To append a scene at the end simple add the scene to the scenes araray:

movie.scenes.push(scene);

To access the first or last scene:

var firstScene = movie.scenes[0];
var lastScene = movie.scenes[scenes.length-1];

Adding a VisualTrack to a Scene

The visual content of a scene is made up from composing VisualTracks on top of each other, much like layers in a Photoshop image. Tracks a stacked in the sequence they appear in the tracks property of a scene, i.e the first track is at the bottom and the last track is on top.

In contrast to Photoshop, VisualTracks are sequences of frames, not a single image. Therefore, in most cases, VisualTracks have a length. To set the length (or duration) of a track, specify the number of frames in the numframes property. If the length of the track cannot be specified beforehand, the numframes property is set to -1.

var track = new sdl.VisualTrack({numframes: 100});
scene.tracks.push(track);