ClientTracker Class
A Tracker represents a Target Collection which is created with
the Target Management Tool.
A Tracker needs to include the binary .wtc targets describing the targets and
needs to be referenced via a URI. The Tracker object is used to reference
specific Trackable2DObjects (the targets inside the target collection).
Trackers can be enabled and disabled. Only one Tracker can be active at a time. The current enabled/disabled state of a Tracker is reflected in the enabled property. Should there be multiple Trackers used in the ARchitect file, the following logic applies to specify the currently active Tracker:
- When a new Tracker is created, it is automatically set to the active one, unless it was created with enabled set to false.
- When a specific Tracker is enabled, it is automatically set to the active one. The previously active Tracker is disabled by the system.
// a Tracker referencing a target collection on a server var tracker1 = new AR.ClientTracker("http://myserver.com/targetCollection1.wtc" , { onDisabled : function(){ //tracker has been disabled by the system } }); var enabled = tracker1.enabled; //true // a second tracker, which will cause tracker1 to be disabled var tracker2 = new AR.ClientTracker("http://myserver.com/targetCollection2.wtc"); enabled = tracker1.enabled; //false enabled = tracker2.enabled; //true
Constructor
Item Index
Properties
Events
Methods
destroy
()
Destroys the object.
Properties
enabled
Boolean
The current activity state of the Tracker. This property might by changed automatically by the system, in case another Tracker is enabled, causing this Tracker to be disabled. The onDisabled trigger will be called in this case.
physicalTargetImageHeights
Object
Use this option to specify the physical height of a image target that is included in the .wtc file. These options are only necessary if the distanceToUser functionality is used and the .wtc file version is below 4.1. The physical height is expressed in millimeter, and this object contains a map using target names as keys.
src
String
The URI pointing to the referenced target collection. The property is read-only and can only be set on creation.
Events
onDisabled
The trigger fires when the Tracker has been disabled by
the system. It does not fire when enabled is set to
false manually.
The trigger is null by default, and will thus result in no action executed when the trigger fires. A developer can add custom functionality by assigning a custom function to onDisabled.
onError
The trigger fires when the Tracker's target collection
could not be loaded. Causes for this might include bad
network connection or a corrupt target collection.
The trigger is null by default, and will thus result in no action executed when the trigger fires. A developer can add custom functionality by assigning a custom function to onError.
onLoaded
The trigger fires when the Tracker's target collection
was successfully loaded. TrackableObjects related to
this Tracker can only be tracked after the Tracker was
successfully loaded.
The trigger is null by default, and will thus result in no action executed when the trigger fires. A developer can add custom functionality by assigning a custom function to onLoaded.