Bij GameSpot valt te lezen dat John Carmack gisteren op QuakeCon 2001 een kleine real-time demo heeft laten zien van het spel Doom III. Volgens de aanwezigen indrukwekkend. De nieuwe Doom engine verschilt visueel voornamelijk van de Quake III engine in de manier van belichting. In plaats van voorberekende light maps wordt er gebruik gemaakt van een real-time per-pixel lichtmodel. Daarnaast wordt er zwaar gebruik gemaakt van bumpmapping en andere texture effecten om de kwijlfactor van het spel te verhogen. Dit alles vormt wel een zware belasting voor de videokaart. De bedoeling is dat het spel op een GeForce3 met 30FPS loopt:
The most dramatic scene in the demonstration took place in a white-tiled bathroom. A dead body was seen lying on the ground when a pink demon walks up to the cadaver and takes a bite out of its stomach, disemboweling it. The demon, a creature returning from the original Doom games, has been transformed by the leap in graphics quality, and now can be seen walking lithely on its four feet in a way that conveys frightening power. Another scene showed a demon walking through a flaming environment, full of particle-based sparks. A more action-filled shot centered on a Strogg breaking through a many-paned window, shattering the glass in a leap that could have been straight out of a sci-fi action film.
John Carmack went on to talk about what makes the next Doom engine a generational leap beyond Quake III: Arena. The big visual difference is due to a per-pixel lighting model that will require an average of five to six rendering passes on GeForce256, GeForce2, or Radeon cards, which represent the minimum that id plans to support for the game. The effects on some individual pixels in a scene may require up to 50 passes (graphics chip clock cycles). The game is intended to run at 30 frames per second on a GeForce3 with all visual options on, although it will certainly be faster on future hardware.