Post-Mortem

At GDC11 earlier this year, there were a whole bunch of postmortems on classic games to celebrate the conference's 25th anniversary. These postmortems are now up for free viewing on the GDC Vault, including a Doom postmortem by John Romero and Tom Hall.

What does a "post-mortem" of a game mean?!

It's a business buzzword.

oh man I heard about these on the giant bombcast and was so jealous, and now here they are released for free! effing makes my day. gonna watch the doom one when I get home tonight.

Man the audience doesn't even laugh under their breath at anything they say, despite some of their jokes being kind of funny!

For anyone involved in the DTWID project, I advise that you take a very good look at the video featured in the second link here and drink in as much info as you can, especially from 22 minutes in with "E1M2 development". Fountains of knowledge!

Ralphis said:

Man the audience doesn't even laugh under their breath at anything they say, despite some of their jokes being kind of funny!

Yeah, it all looks pretty lazy. There must be a few members here who would have given an arm and a leg to be present at the talk, well prepared to ask questions more intuitive than the ones offered at the end of the video. Most of it was blithering.

Wow, Tom Hall sounds so generic compared to his work as Walton Simons in Deus Ex or even El Oscuro in ROTT. :P

Very interesting. I didn't realize how important Tom Hall was - I knew he wrote the bible, but didn't know that he pushed for so many gameplay features. Without him and Romero the game would probably have been incredibly sterile. It's pretty obvious that id is really lacking a Hall/Romero figure in their post-Quake games.

That was a splendid little presentation. I appreciated when they decided to talk about some of the coding details and reflect on specific gameplay mechanics.

I must be blind because I could of sworn I didn't see this post just a few minutes ago..

Anyway, it's a pretty cool video.

A very interesting watch.

It really is amazing seeing how this awesome game evolved over the mere course of a year. Writing such a complex and efficient engine in such a short time frame is just breathtaking. I can't imagine a better team of developers pulling it off... Doom wouldn't have been Doom without Carmack, Romero, Tom, and Adrian.

david_a said:

Very interesting. I didn't realize how important Tom Hall was - I knew he wrote the bible, but didn't know that he pushed for so many gameplay features. Without him and Romero the game would probably have been incredibly sterile. It's pretty obvious that id is really lacking a Hall/Romero figure in their post-Quake games.

The whole game industry is lacking Hall/Romero figures these days, because the suits ran out all the creative people in preference for people who put up, shut up, and churn out the next iteration of an existing plastic guitar or military co-op simulation game.

As for the video, while it was fun to watch, I think Romero just went through the DOOM wiki to remember some things to mention because there was literally nothing, except for the funny bit about the last-minute timer glitch, that isn't on there somewhere ;)

Quite an interesting video - seems to mirror what my degree was expecting me to manage this year too, so I can sympathise with the situations they described.

Most of the content covered was pretty self-explanatory: some of Romero's anecdotes sound like they were straight from Masters of Doom, but I still really enjoyed watching this and hearing these accounts from their own perspective.

The insight into the early Doom builds really shows how Carmack was and continues to be, well, not a bad developer per se, but he really seems to have few qualms about making cuts for the sake of performance and getting the project out the door. I was amused to hear how Romero's steadfast defense of his abstract level geometry indirectly led to the creation of binary space partitioning. I'm still amazed, personally, at how quickly id Software got this game done so quickly. Truly dedicated people...if only they were still as prominent in the industry as they once were.

StoneFrog said:

I was amused to hear how Romero's steadfast defense of his abstract level geometry indirectly led to the creation of binary space partitioning.

It didn't. It led to the usage of BSP in Doom and as a result many other engines to follow it.

So, I guess I have a question regarding that. Before Doom was using binary space partitioning, did maps have to be "compiled" before they were run? From what I understand, some of the map lumps, namely SSECTORS, SEGS, and NODES, store a breakdown of the map geometry defined by LINEDEFS, SIDEDEFS, SECTORS, and VERTEXES. These are obviously related to the use of BSP. So before BSP, was Doom using another node format, none at all, or was it doing something similar to Wolfenstein?

I really like how 'God Mode' in ROTT came to be thanks to John Romero making moaning noises while no clipping in Wolfenstien.. heh

EarthQuake said:

So, I guess I have a question regarding that. Before Doom was using binary space partitioning, did maps have to be "compiled" before they were run? From what I understand, some of the map lumps, namely SSECTORS, SEGS, and NODES, store a breakdown of the map geometry defined by LINEDEFS, SIDEDEFS, SECTORS, and VERTEXES. These are obviously related to the use of BSP. So before BSP, was Doom using another node format, none at all, or was it doing something similar to Wolfenstein?

As far as I've lead to underdtand. No, they did not require node building.

Kaiser said:

I really like how 'God Mode' in ROTT came to be thanks to John Romero making moaning noises while no clipping in Wolfenstien.. heh

The id guys were actually very approving of ROTT, if I recall. There's some photos of Tom Hall playing Comm-bat with Romero and co. at the office.

Of course all this time I assumed the sounds were supposed to be yawns somehow and the origin story behind Romero's noises suggests otherwise.

That was interesting. I didn't realize that BSP was introduced into the game like that. And I never knew of the timer bug.

I'm curious how they experienced the timer wrap around, though. If it was is a 32 bit unsigned this means it will take almost 50 days to wrap. If their timer even used a 16 bit unsigned int would wrap almost every minute, if I did my calculations correct... So unless they had a 24 bit int they would either experience it constantly or (almost)never. But I don't know how it was done. I guess I could always open up the source.

hobomaster22 said:

That was interesting. I didn't realize that BSP was introduced into the game like that. And I never knew of the timer bug.

I'm curious how they experienced the timer wrap around, though. If it was is a 32 bit unsigned this means it will take almost 50 days to wrap. If their timer even used a 16 bit unsigned int would wrap almost every minute, if I did my calculations correct... So unless they had a 24 bit int they would either experience it constantly or (almost)never. But I don't know how it was done. I guess I could always open up the source.

They stated in the video - the value of the variable used to track the time was starting out uninitialized, ie., containing an effectively random value. So if this started sufficiently close to the wrap point, it could roll over during normal play.

That was really cool to watch! Some of this stuff I kinda already know about, especially since I've read Masters of Doom, but it's always fun to hear about the development process this game had.

EarthQuake said:

So, I guess I have a question regarding that. Before Doom was using binary space partitioning, did maps have to be "compiled" before they were run? From what I understand, some of the map lumps, namely SSECTORS, SEGS, and NODES, store a breakdown of the map geometry defined by LINEDEFS, SIDEDEFS, SECTORS, and VERTEXES. These are obviously related to the use of BSP. So before BSP, was Doom using another node format, none at all, or was it doing something similar to Wolfenstein?

The WAD format is one thing that hasn't changed throughout Doom's development, so you can look at the alpha and see for yourself.

In Alpha 02, the single map is comprised of the following lumps: M_AREA, M_FNAMES, M_LINES, M_PLANES, M_PNAMES, M_POINTS, M_TEXTUR and M_THINGS. I'd guess that M_AREA corresponds to SECTORS, M_LINES to LINEDEFS and M_POINTS to VERTEXES. M_FNAMES corresponds to a list of flat names, M_PNAMES to a list of patches. M_TEXTUR seems like it's an early version of the TEXTUREx lumps, but I haven't looked too deeply into it. Not sure what M_PLANES is meant to be.

Alpha 04 introduces multiple maps with a "header then lumps" structure closer to their eventual form. The lumps are FLATNAME, POINTS, LINES, SECTORS and THINGS. Alpha 05 is the same.

Then there is the turning point after that. When the press release beta is sent, the map lumps have reached their final state with just one exception: in the beta, the REJECT lump isn't there yet.

So what's the secret to getting the GDCVault video to play? Someone throw it on youtube please! My computer hates the GDCVault site.

I had no idea Tom was such a cool guy.

StoneFrog said:

I'm still amazed, personally, at how quickly id Software got this game done so quickly. Truly dedicated people...if only they were still as prominent in the industry as they once were.

I agree. Even with the modern tools available today, creating a complete conversion of all the game content is no easy task.

One thing I noticed, I didn't catch any mention of Bobby Prince / sound and music development.

Ed said:

I agree. Even with the modern tools available today, creating a complete conversion of all the game content is no easy task.

One thing I noticed, I didn't catch any mention of Bobby Prince / sound and music development.

Yeah, I noticed that as well. Kind of disappointed by that, really. I guess it didn't fit within the one-hour time constraint... Shame. It's a neat video, regardless.

I am so glad Tom was involved with Doom. I was always under the impression that he left when it was barely started, after they didn't want to use the doom bible.

It would be interesting to dig into the earlier alphas and find the original rendering algorithm based on "sector lists." Then you could extract that code, put it in a modern DOOM port, and see for yourself what its failings were by constructing different maps and trying to run them under it.

Epyo said:

I am so glad Tom was involved with Doom. I was always under the impression that he left when it was barely started, after they didn't want to use the doom bible.

Me too.
I thought all he did was make that, a few levels, and was kicked out of the company because the other id guys didn't like the complexity of the doom bible.