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World Effects
Target Tracker

Target Tracker

A traget tracking effect shown in both the Viewport and Simulator.

Use the target tracker in Meta Spark Studio to trigger an effect when the camera is pointed at an image in the real world, like a poster for a movie.

Adding target tracking

Start by adding a target tracker:

  1. Click Add Object.
  2. Select Target Tracker from the menu.

It’ll be listed in the Scene panel. You’ll also see a square in the middle of the Viewport and Simulator. This square represents the space for the target image:


Add the target image

This is a texture representing the real life image that will trigger the effect. It's a good idea to take a look these best practices to help choose an image that will work well.

To add the target image:

  1. In the Scene panel, select the target tracker.
  2. Go to the Inspector.
  3. Next to Texture, click Choose File....
  4. Select the texture file that you want to trigger the effect.

You'll see the texture appear in the Viewport.


Adding the effect that will be triggered by the target

To add the effect you want to trigger when the camera is pointed at the target, add the objects you want to appear as a child of the target tracker.

Fixed or moving targets

Target tracking effects can either stay in the place where the camera first detected the target image, or move with the target image as it changes position.

To choose one of these options, select the target tracker in the Scene panel and edit the Target Type setting in the Inspector. There are 2 options to choose from - Fixed or Moving.

Fixed targets

The effect will appear at the point where the target image was first detected by the camera. If the target leaves the camera's view, the effect will still be displayed and tracked correctly. The target must stay in a fixed position to get the best results. If the target is moved or removed, tracking may be disrupted.

To further improve tracking when your target is not in view of the camera, you should encourage users to move their camera around the target for a short period of time before the target goes out of camera view.

Moving targets

The effect will move with the target image if the target image changes position. If the camera isn’t pointing at the target, the effect will disappear.


Previously, fixed and moving target trackers were two separate object types. The new target tracker performs measurably better than the older versions, so it's recommended that you update your existing tracking effects. To update effects created with previous versions of the target tracker, open your project file in the latest version of Meta Spark Studio and re-publish your effect.

Properties

When the target tracker is selected in the Scene panel you can view and edit its properties in the Inspector.

Layer

Set which layer the target tracker is assigned to.

Visible

When this box is checked, the target tracker is visible in the effect.

Texture

Add the texture that will trigger the effect.

Transformations

Change the position, scale or rotation of the target.

Enable for

Set whether the target tracker works through the front or back camera, before the effect is captured or during capture.

Interactions

Create simple patch graphs to represent the target tracker.

The target tracker patch

To create a patch representing the target tracker to use in the Patch Editor, drag the target tracker from the Scene panel into the Patch Editor.

A series of 3 patches will be created:

  • Target Finder will find a target image when the camera is pointed at it.
  • Target Select will output a boolean signal when a target is detected by Target Finder.
  • fixedTargetTracker can output the position, scale and rotation of the target in 3D space, and whether a target has been found.
A patch graph representing the target tracker.

Meta Spark Curriculum

Target Tracking Using 3D Assets
In this curriculum lesson, you'll learn the basics of target trackers in Meta Spark Studio. Learn how to create an effect on a poster using a target tracker.

Watch now