Front-facing

So, when we ask you to imagine a cube, your mind will likely visualize only 3 faces. By default, most 3D engines follow the same rule — if a polygon is invisible, it doesn't exist. In other words, they don't render the areas that don't face the camera. It's remarkably useful for performance optimization, especially when it comes to rendering real-time graphics, such as video games. Rendering only front-facing polygons requires less work, takes less time, and in general, is more efficient.^[1]