With the release of the Doom 3 source-code coming up soon (after John Carmack is done addressing a patent issue), it's time to begin dusting off your old id Software Doom 3 DVD/CDs and/or get ready to begin developing new content and games on the id Tech 4 engine. If you're wondering whether or not the open-source Mesa/Gallium3D Linux drivers in 2011 will now work with the id Tech 4 game from 2004, here are some tests of the very latest open-source Intel, ATI/AMD, and NVIDIA drivers under Ubuntu Linux.
Since the open-source version of Doom 3 is not yet published due to the "Carmack's Reverse" patent problem, the Mesa/Gallium3D drivers were tested with the latest release of the Doom 3 Linux binary. That's Doom 3 v22.214.171.1244 from 2007. Carmack's expected workaround for the volume shadow IP issue is expected to deliver similar image quality, but at a slight performance loss if going with the two-pass approach, which means the open-source derived version may perform a bit slower when it comes to handling volume shadows. In terms of any other changes in the open-source Doom 3 / id Tech 4 code, I haven't yet heard of any, but if id Software has stripped away any functionality the open code-base it's likely dealing with the more advanced graphics rendering features.
It will be interesting to see what the open-source community does with the code upon its public debut. Sadly, the open-source community still is not known for coming up with polished art / game assets (plus there's still a lack of viable Linux content creation tools), but hopefully there will be some nice works with the idTech4-derived projects. I am looking forward to possibly making some changes to the engine to make it more interesting for benchmarking under Linux (integrating screenshot capabilities on a timed basis and more verbose performance reports, for use by the Phoronix Test Suite and OpenBenchmarking.org).
For delivering some modern driver benchmarks of Doom 3 under Linux, I used an Intel Sandy Bridge system with a variety of GPUs and drivers. For the open-source driver testing, all of the important components were pulled from Git master on the morning of 16 November. This includes Mesa 7.12-devel, Linux 3.2, libdrm, xf86-video-intel, xf86-video-ati, and xf86-video-nouveau atop an Ubuntu 11.10 x86_64 installation. (Of course, if you follow me on Twitter this article should not come as any surprise.)