Just like Quake 1, if you already own Quake 2, the enhanced version is available as a free update. Although unlike Quake 1, Quake 2: Enhanced is also available on GOG day 1.
In addition to visual updates, there’s a new episode “Call of the Machine”, Quake 2 N64, a pass to the enemy AI which changes a few behaviors and attacks, removes machine gun recoil, a new infinite use item that shows the player where to go next, and a number of other qol and accessibility options.
Anecdotally, I find the addition of Q2 N64 very appealing. It’s a mish-mash of pared-down maps from vanilla Q2 and the expansions in a strictly linear fashion - no backtracking. Of course, there’s also changes to the lighting and a new OST by Aubrey Hodges. Being able to control the game from keyboard / mouse is a godsend. I played the game in emulator with a modern gamepad and it was barely, barely doable, even when I could manually set deadzones and sensitivities and the like. It was awful.
If you think that is a 2007 tech demo then… You clearly don’t remember 2007
But yeah. It isn’t a flagship use of ray tracing (… actually, it is, but that speaks more to the general lack of ray tracing in gaming). But it is a really cool nod to history (since quake 2 was one of the earlier games to have dynamic lighting) that does a good job of making quake 2 look like what we remembered quake 2 looking like (same as you remember 2007 looking like that).
The dynamic lighting never looked ANYWHERE near that good but… in our minds it did.
And it also kind of became a weird time capsule of what ray tracing was. When the two big early examples of RTX were… Minecraft and Quake 2 (Control existed but the specs were already high enough for most folk before you popped the toggle).
Mostly it is just a bit disappointing that something that exists and was mostly official isn’t part of the re-release. But I suspect there are some shenanigans with how nvidia licensed that and so forth.
And as an add-on. Yeah, the RTX is gonna look shit in the outdoor maps. Mostly because of how those were lit, relative to the indoor ones. Most people never got past the first level (or really, first room or two) in Q2RTX and those were some of the best. Because they were meant to show off the dynamic lighting back in the 90s so all light came from sources that had corresponding texture and geometry. So switching to ray tracing makes those lights look a LOT better. Whereas external areas still involved a lot of ambient lighting and multiple fake sources to represent the sun.
It is similarly why stuff like Control and Cyberpunk… didn’t look all that amazing. Because most scenes were not lit solely with “real” lights. Yes, you had the overhead fluorescent and that desk lamp. But you also had ambient lighting to get the right “vibe”. So once you switch from (largely) pre-baked lighting to ray tracing… all of those ambient lights and false sources are now making things look washed out or like they “glow” in the wrong way. Because now you do have realistic ray tracing of the light from the overhead and you might even have the right materials on the walls to get the diffusion of some shitty taupe paint over drywall. But you also now have the light from those “fake” lights being traced too.
I am not up to date on how modern level design works. But if you are really interested? Go look up a few editor tutorials for Unreal Tournament or Quake 3. UT in particular is really easy to see all the lights that get put in the scene before you bake them in. You obviously want to put a light source on the desk lamp mesh. But… you also probably need a few in the hallway to mimic the diffusion that comes from said desk lamp’s light reflecting off the walls.