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World Effects
Target Tracker

Target Tracker

In Spark AR Studio you can create effects that are triggered when the camera is pointed at an image in the real world, for example a poster for a movie. You'll use an object called a target tracker to do this.

You can build a target AR effect from scratch by following this tutorial.

Adding target tracking

Start by adding a target tracker:

  1. Click Add Object.
  2. Select Fixed 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.

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.
  • staticTargetTracker can output the position, scale and rotation of the target in 3D space, and whether a target has been found.
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