+This application uses the _depth_ framework to load and display 3D models.
+It also applies the _flat_ framework to display the static UI elements (like the "Next model" label).
+
+The pretty earth model (`GlobeModel`) is implemented by a material with a custom graphical program.
+It renders the earth with an displaced surface, a cloud layer, city lights and Phong lighting effects on the water.
+
+# Variations
+
+* The standard application is compiled to a desktop executable at `bin/model_viewer` and an Android package at `bin/model_viewer.apk`.
+* The virtual reality variant `bin/model_viewer_vr.apk` targets Android and uses Google Cardboard for head tracking.
+