360-degree media is compelling because VR tricks your FOV by updating the viewable area in real-time as you move your head around, making the screen of your HMD seem to have no edges. We started this chapter by describing what 360-degree images are, as well as how the surface of a sphere can be flattened (projected) into a 2D image by using equirectangular projections in particular. Stereo 3D media includes separate equirectangular views for the left and right eyes.
We began exploring this in Unity by simply mapping a regular image on the outside of a sphere, and were perhaps frightened by the distortions. Then, we saw how an equirectangular texture covers the sphere evenly for rendering a globe. Next, we inverted the sphere with an inverted shader, mapped the image inside the sphere, and made it a 360-degree photosphere viewer that can load photos from the web. After that, we added video.
Then, we looked at using skyboxes instead of a game object for rendering...
