John Romero

John Romero: Never say never. I'm sure something amazing will happen again, but you never know what it will be. The right opportunity has to present itself with all the right elements in place at the right time. Regarding us showing up established publishers back then, what if we had developed DOOM and decided to have Activision or Origin publish it? Everyone would look back at the legendary Origin game DOOM in addition to its legendary Ultima games. Most publishers are publishing games from third parties, but many times it's the publishers who are remembered for those games. I guess what I'm trying to say is that many great games are made by small developers but most people only know the publishers of those games. We were recognized because we published the game ourselves -- basically gave it away for free just so everyone would have it.

John Romero:There's only one John Carmack and back when we created DOOM, no one could come close to John technically. His optimization tricks he created for drawing the walls and ceilings/floors in conjunction with the innovative use of BSP trees was far beyond what anyone was thinking at the time. Those tricks and data structures amounted to incredible rendering speed.

John Romero: The greatest technical challenge was probably figuring out how to render a world without a clipping plane very quickly -- and that's where BSP trees saved us. Originally, John was sorting through sectors to figure out how to draw the scene and this took a bit of time. I presented a problem for him when I was creating E1M2 and created an area of concentric stairs that basically told the renderer it had to draw several sectors multiple times.

Design-wise, our challenge was coming up with a design methodology for the game. Originally, we had a bunch of hallways with little rooms and ceilings as high as those in Wolfenstein. It was like running through a boring office. I came up with some interesting ideas that broke us out of the Wolfenstein-style of design and started exploring large spaces with more complex sector geometry. That's when I started to create a lot of my level design rules like always changing floor height when I wanted to change floor textures; using special border textures between different wall segments and doorways; being strict about texture alignment; conscious use of contrast everywhere in a level between light and dark areas, cramped and open areas; making sure that if a player could see outside that they should be able to somehow get there; being strict about designing several secret areas on every level; making my levels flow so the player will revisit areas several times so they will better understand the 3D space of the level; creating easily recognizable landmarks in several places for easier navigation, etc.