Education is an important application of augmented reality. Children of all ages love astronomy and studying the planets of our solar system. So, for this project, we're going to build an educational AR app that will let you explore the solar system and view the planets in the comfort of your living room.

In this chapter, we are going to build a model of the solar system, including the earth, moon, sun, and the other eight planets (yes, Pluto still counts!). We will use actual NASA data to set up the size and texture of each heavenly body. We will animate the planet's spin and orbit using C# programming.

We'll use the primary AR technique of using coded markers to implement the project. We'll print cards with AR markers you can use to interactively explore celestial bodies. We will also show you how to make a markerless version of the project for devices that support spatial mapping.

In this chapter, you will learn the following topics:

• Building a hierarchy of the solar system with orbiting planets and an earth-moon system with the moon orbiting the earth
• Adding texture maps to objects to make realistic-looking planets
• Adding light to the scene and showing both the day and night sides of the earth
• Writing C# scripts for planet spin and orbits
• Using custom markers to control what is visible in the augmented scene
• Creating markerless AR projects for devices that support spatial mapping

In the interest of clarity, this chapter will first walk you through the entire project, as if developing with Vuforia for Android devices. At the end of the chapter, we will walk through the steps for other development targets, including ARToolkit as an alternative to Vuforia. For markerless implementation, you can consider using Apple ARKit for iOS, Google ARCore for Android, and MixedRealityToolkit for HoloLens.

Alright, let's blast off, rocket man!