One shared element between film, television and video games is the use of on-screen and off-screen in the creation of a diegetic world. However, what is important to remember is that video games added elements of navigation and interaction that led to a diegetic space which is unlike any other media.
Off-screen space in video games is different from what seen on film. In a video game one would see both the representation and implication. Not to mention it doesn’t have a default structure, so it can be shaped n many various ways. The video game is also interactive, allowing the viewer to choose which spaces to appear on-screen or off. Meaning that the player actually can explore off-screen space. (of course there will be technical limitations to the space, but that depends on a lot of different variables).
The author then list different spatial structures to explain that there are a lot of different spaces that has their own niches. 1. No visual space; all text-based and example on this would be The Hitchhiker’s Guide to the Galaxy (1984). 2. One screen, contained and example would be Spacewar!. 3. One screen, contained, with wraparound(objects leaving one side of the screen and immediately reappear on the opposite side) this would for instance be computer space (1971). 4. Scrolling on one axis and example would be Street Racer (1978). 5. Scrolling on two axes an example would be SimCity (1989). 6. Adjacent spaces displayed one at a time, an example would be the arcade game Berzerk (1980). 7. Layers of independently moving planes (multiple scrolling background) a very good example for this would be Super Mario Brothers. 8. Spaces allowing z-axis movement into and out of the frame, Atari’s Battlezone (1980) is an example of this. 9. Multiple, nonadjacent spaces displayed on-screen simultaneously, Atlus’ High Velocity (1995) is an example of this. 10. Interactive three-dimensional environment an example of this would be Dragon’s Lair or Myst. It all depends on the camera and navigation available. 11. Represented or “mapped” spaces, Defender (1980) is an example of this.
The author then suggests different ways to create a 3D space, using various games as examples of different methods. However, as long as one has a strategy it should be possible to work something out, even with limited resources. Because there are many different methods to do so, not to mention that the video games over the years has become more and more convincing and photorealistic.