Detecting planes

An essential part of programming an AR game is adding the ability to detect features in the environment. These features can be objects, faces, images, or in our case, planes. A plane is any flat surface with a specific dimension and boundary points. Once we've detected a plane, we can use its details to spawn a turtle at the correct position and with the proper rotation.

We'll detect planes using ray casting and a custom script. However, before we write the script, we'll first add a Plane Manager to the scene.

Adding a Plane Manager

A Plane Manager will generate virtual objects that represent the planes in our environment. We'll use these virtual objects as a guide to where we can spawn the turtle. It will also provide useful debug information by drawing a boundary around any planes it detects. Using this feature, we can see in real time when Unity has detected a plane:

1. Open the ARScene located in the Assets/Scene folder.
2. As...