id Software Finally Releases Edited Doom 3 Source Code
As promised, id Software has released the source code to Doom 3 although it's been slightly altered to avoid a possible patent dispute with Creative Labs.
On Tuesday id Software quietly released the source code behind the studio's 2004 shooter, DOOM 3. Naturally the code doesn't contain any game data, as the DOOM 3 material is still covered by the original EULA. However the source has been altered slightly to avoid possible patent disputes related to Creative Labs' 3D shading technique called "depth fail."
"Lawyers are still skittish about the patent issue around 'Carmack's reverse,' so I am going to write some new code for the doom3 release," John Carmack said via Twitter. "This demonstrates the idiocy of the patent -- the workaround added four lines of code and changed two."
During DOOM 3's development, Carmack independently discovered and publicized a shading process later dubbed as "Carmack's Reverse," but Creative Labs had already filed for a patent on the technique back in 1999. Carmack said he created a separate shading method that got around the patent issues, but that meant a significant "speed hit" in DOOM 3's performance. Thus, the studio had no choice but to license the "depth fail" patent from Creative and move on.
"The Doom 3 GPL source code release does not include functionality enabling rendering of stencil shadows via the 'depth fail' method, a functionality commonly known as 'Carmack's Reverse,'" states the source code notes.
To get the DOOM 3 source code, head here via Github.

I feel there is something fundamentally wrong with this whole process of patenting.
I feel there is something fundamentally wrong with this whole process of patenting.
http://www.angelfire.com/games5/duktroa/RealTimeShadowTutorial.htm
WOOOOOOOOOOOOOOO!!!!!!!!!!!!!
I will admit it's been disturbing that starting with Quake, each engine has taken longer from the release of the initial game to it being GPL'd as open-source: 3 years for Quake, (1996->1999) 4 for Quake II/Id Tech 2, (1997-2001) 6 for Quake III/Id Tech 3 (1999-2005) and now 7 years for Doom 3/Id Tech 4. (2004->2011)
Its not dogmatic. It is on principle, and one that I embrace. OpenGL is an open standard for graphics technology, that is cross platform and can be implemented on any video device. DirectX is a Windows wrapper layer for video that is proprietary to Microsoft and thus can't be cross platform, ever.
You would think that OpenGL meant the burden of implementation fell on drivers, but it does even with DirectX, every new game (like Skyrim) Nvidia / AMD are in a race to release hacked drivers that optimize whatever DirectX calls new games use, without actually knowing the implementation of DirectX in the OS. Either way you go, the drivers change on a daily basis.
DirectX is just M$ getting in the way of graphics technology. OpenGL applies to everything from cell phones to rendering farms for animation to web based applications. DirectX is only ever used in gaming, and only because M$ has a ridiculous grasp on the PC gaming market, BECAUSE of their psuedo-monopoly where everyone uses DirectX, and thus Nvidia / AMD have poor OpenGL compliant drivers, etc.
OpenCL though, will probably revolutionize this entire shebang. I expect Carmack to write id 6 almost exclusively with OpenCL to crank out whatever ounce of performance per frame he can come up with. Where OpenGL is an abstraction library of binary function calls that are generalized across platform and provided by the driver, openCL is a language wrapper that lets programs execute direct GPU commands like on the 360 and ps3, which is what he was talking about at the Quakecon keynote.
Even the last game released on this engine in 2009 ( Riddick: Assault on Dark Athena) was totally dated graphically even 2 years ago.
Brink uses IDtech 4 and the upcoming Prey 2 uses it as well, so I wouldn't count it as dead yet. Hell UE2.5 is still being used and it is just as old.
Wow, guess I am ignorant. That's pretty crazy, but I guess it's been updated A LOT since it's release.
Though, I'd like to see a DirectX-like API to go cross platform. That would be awesome.
Apple has shown us this more than any other company. We all KNOW there is something wrong with the patent system, the problem is no one is doing anything about it.
Maybe I'm ignorant, but what is the purpose of this? Is anyone going to use this ancient engine for anything? Even the last game released on this engine in 2009 ( Riddick: Assault on Dark Athena) was totally dated graphically even 2 years ago.
Your statement is wrong on every level. Not only are there new games coming out using the engine, Dark Athena didn't use it at all.
I just discovered both of these Riddick titles used the Starbreeze Engine, my bad.