This guide walks through the various tracking modes Lens Studio offers for world experiences.

Device Tracking

The Device Tracking component allows you to place objects in your Lens Studio experience that will be locked to the world. When run in Snapchat, the content will appear in front of you at the start of the Lens. The Device Tracking component has three modes:

• Rotation: Users can rotate their phone and have the objects stay locked relative to their orientation. Users will not be able to walk towards, away from or around the content
• Surface: Users are able to walk towards, away from and around the content, in addition to being able to rotate their phones. When Surface is selected, you have the option to also enable Use Native AR. With Use Native AR enabled, the device's native AR tracking capabilities will be utilized to enhance tracking
• World: Users are able to walk freely through the scene without focusing on a surface. This mode solely relies on the device's native AR tracking capabilities and falls back to a Rotation experience if native AR tracking is not available. For most use cases where you want to take advantage of native tracking, we recommend instead using Surface with Use Native AR enabled because it will fallback to Surface if native tracking is unavailable

Note
Surface mode tracking works best when content is scaled roughly human size or less. For anything bigger, consider enabling Use Native AR as well which will utilize the device's native tracking capabilities if available. When Surface mode is enabled, content in your scene is attached to the ground. Surface mode does not understand or detect walls or obstacles (like a couch or coffee table).

Adding Device Tracking

To add Device Tracking, first select the Camera object in the Objects panel. Then, in the Inspector panel click the Add Component button and select Device Tracking.

When Device Tracking is enabled, you'll see a green grid in your Scene panel indicating that Device Tracking is turned on. Any object in the scene will now be attached to the world.

Choosing Device Tracking Mode

By default, Surface mode is used in the Device Tracking component. To change this, in the Inspector component, press the Tracking Mode drop down and select an option.

Using Surface Mode

Surface mode is useful for when you want to allow users to walk up to your content, as well as walk around it. For experiences that encourage the user to more freely walk around (like a portal) or for larger content, consider enabling Use Native AR which will utilize the device's native tracking capabilities if available. 

Positioning Object in Surface Mode

When you use Surface tracking mode, Manipulation can be added to any object allowing the user to move, rotate and scale objects. To add Manipulation follow the Manipulation guide.

For an example of the Device Tracking component in-use, please refer to the Static Object Template.

Choosing Tracking Point in Surface Mode

As you move your object around on a surface, the further it gets from the origin the less stable the tracking can become. Telling the Device Tracking system what the tracking target should be can significantly help this. Each time you start your lens you can reset the device tracker's target with a very simple script. Create a new script named SetSurfaceTrackingTarget.js and add below to the contents.

// -----JS CODE-----
// @input Component.DeviceTracking deviceTrackingComponent
function onSurfaceReset(eventData)
{ 
    if(script.deviceTrackingComponent) 
    { 
        script.deviceTrackingComponent.surfaceTrackingTarget = script.getSceneObject(); 
    }
}
var worldTrackingResetEvent = script.createEvent("WorldTrackingResetEvent");
worldTrackingResetEvent.bind(onSurfaceReset);

With the object you want to be the tracking target selected, add a new Script Component and set it to the SetSurfaceTrackingTarget script. Make sure the event dropdown is set to Initialized. This object will now be the device tracker's target.

Using Rotation Mode

Rotation mode takes the device's gyroscope rotation and applies it to whatever object it is added to. The primary use case for the Device Tracking component with Rotation mode is to have the scene's camera rotation be driven by the device's gyroscope. This will allow you to place content all around the user in 3D space and give the user the ability to freely look around the scene. It is useful for when you want to surround the user with content, but not necessarily walk towards it. 

For an example of Rotation mode in-use, please refer to the Look Around Template.

Marker Tracking

The Marker Tracking Component allows you to track content to images in physical space. An ideal use case for Marker Tracking is a Lens that overlays content on a real poster or mural.

To learn how you can add Marker Tracking to a Lens, visit the Marker Tracking guide. You can also try out the Marker Template and Marker with Snapcode Template to get started with Marker Tracking right away.

Object Tracking

Object Tracking allows you to attach images and animations to certain objects found in the scene. Object Tracking currently supports the detection and tracking of a Cat, Dog, Cat and Dog, Hand and Body. Each Object Tracking type offers various Attachment Points to attach content to. 

 

 

To learn how you can add Object Tracking to a Lens, visit the Object Tracking guide. You can also try out the Pet Template, Hand Template, Shoulder Template, Skeletal Template, Full Body Triggers, and Full Body Attachments to get started with Object Tracking right away.

Camera Attached

You can attach an object to the camera. This is great for simulating a first person object (For example: a magic wand pretending to be in the user's hand). To do this, in the Objects panel, drag the object you want to be attached to the camera to be a child of the Camera object.