Collection in Anark Studio 2.5

A collection of items, accessible by index or name.

Collections of items in Anark Studio are used to provide access to child objects of a node. Available collections are scene.layers, someAsset.behaviors, someAsset.sounds, someAsset.music, someNode.cameras, someNode.groups, someNode.lights, someNode.models, someModel.materials, someMaterial.maps.

The instances returned by accessing the above properties do not inherit from a Collection class; for example, scene.layers.constructor is Object and not Collection. Instead, they are custom instances of the Object class with properties and behaviors defined by this page.

Although they are not arrays, collections can be accessed similarly. They have a length property and integer properties providing access to each child member. For example:

var allLayers = scene.layers;
for ( var i=0, len=allLayers.length; i<len; i++ ){
   allLayers[i].transparentBackground = false;
}

In addition to being accessible by index, collections create a property for each named child object, providing access to that object. For example, given the following scene hierarchy…

• Scene
  • Layer1
    • DiceGroup
      • Cube
      • Pip1
      • Pips2Group
        • Pip2_1
        • Pip2_2
      • …

…both of the following code lines to refer to the first pip in the second group:

var pipA = scene.layers[0].groups[0].groups[0].models[0];
var pipB = scene.layers.Layer1.groups.DiceGroup.groups.Pips2Group.models.Pip2_1;
// pipA and pipB refer to the same model.

Finally, you should note that if you want to access objects in the scene hierarchy by name (the more flexible and robust approach), you rarely need to use the collections discussed here. Not only does the runtime engine create named properties for each model in the collections, it also creates the same named properties directly on the parent object itself. For example, a third (terser) way to access "Pip2_1" in the above example is:

var pipC = scene.Layer1.DiceGroup.Pips2Group.Pip2_1;
// a third way to refer to the same model

The collections discussed herein are most useful when you need to iterate every object of a specific type, or when you have given the same name to two child objects of different types. For example, scene.Layer1.Bounce would be ambiguous in the following hierarchy:

• Scene
  • Layer1
    • Bounce (a Behavior)
    • Bounce (a Sound effect)

In a case like this, the sounds collection can be used to clarify which object is being referred to, i.e. scene.Layer1.sounds.Bounce.