Doom 3 Post Mortem

The Aftermath

Perusing the source code of id-Tech 4, the engine responsible for creating the legendary title, Doom 3, I found it interesting the way the game was structured and the routes and conventions the developers decided to go with when putting the engine together. Delving further into the topic, I stumbled upon a rather interesting talk on the Postmortem of Doom seventeen years after the game was released. The talk was both informative and funny (as game developers often are). The following blog is a summary outlining some of the key points of the talk that I found particularly fun to discuss among the general public. And of course, if you haven't played Doom yet, GO! Seriously, why are you still reading this? Go play it. Now. Please? 

The information on this blog was a result of the viewing of John Romero and Tom Hall's talk on Doom's Post-Mortem at GDC 2011 and can be found here. 

In the Beginning

In 1991, Id Software was composed of four individuals, artist Adrian Carmack, programmers John Carmack and John Romero, as well as game designer Tom Hall. Towards the end of 1991, Steve Jobs came out with something called a 'NeXT' computer which peaked the interest of the team at id. After an $11,000 investment on the NeXT computer, id went on to develop Wolfenstein 3D for DOS, using the NeXT Cube for the game's hint manual. They were asked to port the game over to the Super Nintendo and so the had a developer come in and work on this while the team continues pursuing other titles. 

After a series of FPS games (Hovertank One, Catacombs 3D, Walfenstein 3D, Spear of Destiny) with which the team had plenty of time to experiment with textures and tools of the trade, id decides to try something different with Doom - but we all know that's not really true at all. After brainstorming ideas for Doom and after a lot of Dungeons and Dragons, the guys at id decided to make a game with demons and by the end of November Tom Hall had already created a Doom Bible. The Bible was meant to be more of a design document for the game, outlining where all the levels were, the nomenclature, the tools, the progressions one goes through, etc. Hall was interested in pursuing a level-by-level progression through the game to give the player checkpoints where they could feel a sense of accomplishment upon completion of a rather difficult level. At the same time, John Carmack was beginning to think about the tech involved in the production of such a game. He began by laying down some of the data structures and upon stepping back and taking a look at the system as a whole wanted the game to appear as a singular giant world. At this point, the team begins projecting their memory usage for a project this big soon realizing that their scope was far too large to begin with. After weeks upon weeks of intricate design, Hall is told that there's no way for them to be able to fit all his designs within the final game. There just wasn't enough memory (only about a megabyte allowed). It was quite apparent that as a programmer, Carmack was trying to get the latest technology out on the market with Doom while Hall was trying to give the game the best and most innovative design causing both members to clash heads. 

Coming together

During the production of Doom, there was never a time when the guys at id would draw something, think about where to go with it and then decide whether or not to put it in the game. Once an asset was drawn, once an idea was put on paper, it was definitely going in the game. By January 1993, the technology and the art was in the works and feeling quite confident with their abilities, the team decides to put out a Press Release stating their hopes and aspirations for the game as well as the main features they intended on having (three or four of these didn't even make it into the game). Adrian Carmack , the studio's artist, modeled figures in clay and then put them in front of a camera that would read the model and represent it pixel by pixel. Unfortunately the lights placed on the clay figures would cause them to melt making this method inefficient. 

Id had the engine itself up and running relatively quickly and took some screenshots and alphas of the original stages of development. While Hall attempted to mimic military building designs for levels, Carmack tried to stress optimization and making the game run as smooth and as fast as possible. Due to Carmack's concerns with every environment's polygon count, Hall had to get back to the drawing board and design orthogonal and occlusive shapes. Hall ended up making a bunch of levels composed of blocks which weren't much more than corridors with rooms to go into. Around this time they were also experimenting with the U.I., shooting designs back in forth between Hall and Adrian Carmack (the designer and the artist). The team actually went out and bought toy guns and held them in front of the camera to model their final designs behind. 

Doom - Evil Unleashed was the first pre-alpha release of the game using the data structures Carmack had come up with and all the current designs implemented for testing purposes. With their initial designs, the team realized that the player wasn't getting much of a good view due to too much UI "crap" as they call it. Luckily the game was at a stage where if things didn't work too well, they could afford to just take it out. 

In March of the same year, 20th Century Fox contacted the team at id and offered them the license to Aliens in order to produce a game based on the movie. Although the entire team were big fans of the movie, they decided to turn the offer down in exchange for continuing to run with their original idea for Doom. 

Work continued on as scheduled and now Romero was attempting to make the levels feel a little bit more realistic and recognizable experimenting with contrasts in room height and lighting.   

Disaster strikes and Doom continues

Remember earlier when I told you that someone tasked id to port Wolfenstein 3D to the Super Nintendo? Do you remember when I said that they had a guy working on it? Well that guy didn't manage to finish on time and Imagineer (the company that requested the port) was not pleased at all. It had been nine months since they had been in contact with Imagineer and when asked about the status of the port, id realized that they couldn't get a hold of the guy working on it and would have to halt production of Doom to fix this problem. In the end, they managed to push the final game out in an amazing three weeks. 

Once Doom resumed production, something truly great took place. After a recursion problem with receding stairs, John Carmack noticed that the game was beginning to look really good and instead of asking Hall to fix the design, he took it upon himself to solve the problem so that the aesthetics could live on. The resolve of this problem eventually lead to the BSP Tree (based on the idea by Bruce Nailer) which helped with helped cull out non-visible sectors inside of a level. 

On April 2nd, 1993 id felt confident that they had reached what felt like an Alpha milestone in Doom's production and so made the decision to release the game in its current stage to Beta testers. In May, the team released another Pre-Beta build of the game which featured a lot more textures, a better UI, a menu system, skill levels and monsters of varying difficulties. In addition to this, the game run a lot smoother and started looking more and more like the end product. 

In June, Computer Gaming World (a very popular magazine) did a preview of Doom right in the middle of development. By July, Doom had a lot of variety in monsters thanks to Hall fighting to have constant surprises for the player in terms of enemy types. Despite this win, Hall felt he was being restricted creatively and that his designs were constantly being shot down in pursuit of a faster-paced shooting game. In August of 1993, Tom Hall decides to leave id and goes to Apogee where he works on Wolfenstein II for a bit before creating Rise of the Triad and Prey. At the end of the day, this worked out best for everyone on the team since Hall was happily able to release his creative juices while Romero and Carmack could go back to doing awesome stuff with Doom on the programming and optimization side of things. Neither side was weighing down the other anymore. 

The Final Stretch

After Hall departed from id, the team hired a couple of developers (Dave Taylor and Sandy Peterson) to help with finishing the game on time. Into September the team was making good progress on the automap in addition to pumping out tons of levels and adding DMX sound drivers. In October, a pre-release is revealed two months from release with a lot more textures, a better-looking UI, way better lighting and just overall playable environments that worked well with the theme of Doom. Players could pick up items and the game would keep track of them. At the time, Romero considered the game pretty new school and so decided to avoid the arcade tactic of setting a player back to the start once all their lives were depleted. Instead, he had the player reset to the beginning of the level upon dying as well as a save feature which allowed players to save at any point during the game, down to the second giving way to a high probability of players actually getting to the end of the game and beating it. The next step seemed to be the final game. 

November comes around and the first IPX multiplayer was created as was Deathmatch, co-op mode, the game's final systems, intermissions, menus, installation, text files and serial code for modems. All the game maps were also modified for Deathmatch and co-op play. The development team was spending more and more time at the office putting tons of polish on the game while hype steadily grew thanks to fans in eager anticipation of a game that had been in production for a year now. 

In the final stretch the team pulled a 30 hour no-sleep work session where everyone would be running the game on every machine looking for last-minute bugs. A bug concerning the timers the game had implemented arose but luckily the team had so much experience with the engine and tech at this point that fixing it didn't take all that long. Finally the game was uploaded to the University of Wisconsin's FTP server essentially crashing the entire server and preventing anyone from logging on to download the game while the entire file was being uploaded.

And the rest is history ladies and gentlemen...

In Conclusion

As Game Developers, we stand to learn a lot from id's experience with creating Doom. There were conflicts, setbacks and technical difficulties but what remained constant was the team's strong belief in the game and where it would go. They also believed in each other's abilities and everyone pushed to put the best of themselves into the game. I think we can all agree that the game industry is grateful for the efforts of the team at id in producing a beautiful and well-functioning title that is still held in high regard within the hearts of Game Developers everywhere.