One of the three components of a great game is the user interface, with the others being a challenge and an intuitive concept. Console games come with their own controllers, which now include motion sensors such as in the Wii. Some games have their own controllers, such as the guitar for Guitar Hero. Smart phones beginning with the iPhone introduced the touch screen, leaving only a few simple buttons on the sides and the bottom. With few external buttons, the user interface will reside inside the game—this is an ideal scenario for WebGL.
There are two basic types of user interfaces inside 3D environments: Head-Mounted Display (HMD) and billboarding. HMD is often depicted as glasses or helmets with LCD screens. This may become more commonplace with Google Glass and Oculus Rift VR glasses. In our example, the user interface will be a virtual HMD, where the controls are overlaid onto the 3D scene. Billboarding is the other interface...
