In this example we will use non-optical tracking technology in our scene. Getting location information from the device itself, we will load two POI (points of interest) or billboards North and South from our current position. Then we will add 3D model in the West direction from us. By exploring the scene user has to turn the device around it to discover the objects.
In this tutorial we also introduce LLA coordinates of a virtual object. LLA stands for latitude, longitude and altitude and is a format for defining geo positions on the globe. While the altitude is measured in meters above sea-level, the latitude and the longitude are measured in degrees.
Also integrated into this tutorial is a new feature called radar introduced in metaioSDK 4.1 release. It is quite similar to the radar object presented in previous release of Junaio. In a nutshell, the radar object shows the number and also the location of geometries added to the radar according to the field of view. It provides useful information to users in a location-based tracking application.
Few things to understand on the resources side. In Tutorial5/Assets5 in iOS and assets/Asstes5in Android you can find
- POI_bg.png is a background image for billboards we will be using.
- radar.png is a background image for the radar object.
- yellow.png is a small yellow dot that represents a geometry in the radar.
- red.png is a small red dot which represents a geometry in the radar that has been touched.
If you are planning to use billboards in AREL in location-based scenes, make sure that you have downloaded billboard image sets for iOS and Android. The former one has to be simply added to your Xcode project and latter one has to be placed in res/drawable-nodpi folder in the Android project tree.
Before loading content we first set the tracking configuration of the scene using keyword GPS, as in the code snippet below.