An early premise of this project was to use markers to trigger the solar system AR graphics at the target location and use the bar code on the markers to select the planet or sun-centric view. There is an alternative markerless approach to AR, one that Microsoft coined as holographics.

With holographics, or anchor-based AR, the viewing device is able to scan your environment and map its 3D space. When you add an AR graphic to the scene, it is anchored at a specific 3D location. It uses its sensors to scan and model the 3D space.

This type of AR scene does not use target recognition. Target images and markers are not needed, nor are they usually supported in the toolkits. Therefore, we do not need to use Vuforia at all. We will do our iOS implementation using Apple ARKit and our HoloLens implementation using MixedRealityToolkit for Unity from Microsoft.

We used markers to select which planet to view in the center of the scene; the user experience will be different here. For a handheld smartphone or tablet device, we can use the touch screen for user input. For a wearable smartglasses device, we can use gaze and click or the hand gesture input. For the present chapter, we will keep this basic.