Three-dimensional models are everywhere, from mechanical engineering of machine parts to medical imaging; from video game design to 3D printing. 3D models are as prolific as photos, videos, music, and other media. Yet, while browsers and apps have native support for other media types, 3D models do not have so much. One day 3D viewing standards will be integrated into the browser (such as WebGL and WebVR). Until then, we'll have to rely on plugins and sister apps to view our models. Free 3D file models in the OBJ format, for example, can be found online, including TF3DM (http://tf3dm.com/), TurboSquid (http://www.turbosquid.com/), and many others (http://www.hongkiat.com/blog/60-excellent-free-3d-model-websites/).
In this project, we will build an Android 3D model viewer app that lets you open and view models in 3D using a Cardboard VR headset. The file format that we'll use is OBJ, an open format first developed by Wavefront Technologies for cinematic 3D animation...