Trackers and Targets
Trackers detect and follow real-world objects, defining the coordinate system for your experience. All targets and content are anchored to the tracker’s frame of reference. Only one tracker can be active at a time in a view, but you can include multiple trackers. A default tracker is added automatically, or you can add one using the API.
Targets represent the real-world items you want Vuforia View to recognize and track. These include images, objects, areas, and ThingMarks—a uniquely identifiable marker that also functions as a target. You can add multiple targets to a view. All targets are children of the tracker. Except for image targets, only one target is tracked at a time.
Use the following JavaScript functions to manage tracking:
• getTracked()—Returns a list of tracked target names.
• resetSpatialTracking()—Resets the current tracking state.
• addMarker()—Adds a target to the experience. The source can be any supported target type.
For a full list of supported target types, see “Tracking” in Core Components and Concepts.
For related JavaScript functions, see Tracking Functions.
Content
You can add and modify content for each target in your experience. Content includes 3D models, 2D elements, metadata, animations, navigation, and more. In most cases, content is accessed through a widget using:
$scope.view.wdg[‘id’][‘attribute’]
For an example, see Show or Hide the View Navigation Menu.
To view available parameters for each widget, see the individual widget pages.
Metadata
Metadata includes the structure, properties, and relationships of your imported assets and models. Use this metadata to identify part locations, display model attributes, or trigger other interactions in your experience. For example, you can retrieve a model’s metadata using the following function:
PTC.Metadata.fromId(modelName).then((metadata) => {
//…
});
For more information, see the following resources:
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When importing a model, the Allow Experience access to CAD metadata checkbox must be selected to access your model’s metadata.
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Structure
Each model and its parts have a defined structure. This structure includes the location and bounding box of each part in 3D space. Use this information to determine the position and orientation—both translational and rotational—of models and their components. For example:
PTC.Structure.fromId(‘modelName’).then( (structure) => {
// Do something with ‘structure’
});
For more information, see Incorporate 3D Model Structure Bounding Box and Location Data
Into an Experience.