Valve may be set to upgrade the Source 2 engine that powers everything its released since the mid-2010s with Nvidia's RTX-driven ray tracing and deep learning super sampling. More importantly, that will mean any future games it releases using the engine will get those effects at release, rejuvenating the Source 2 engine with some of the most modern rendering techniques in game development.
Rumors of this change appeared on Twitter late last night, with one user spotting that the most recent Artifact Beta got "Raytracing Shader" and "RTX" strings added to its codebase. If Artifact can do it, so can the other games — it would need to be added by Valve to each game and tweaked to work correctly, but if Source 2 can do it, then all of them can, in theory.
— Pavel Djundik (@thexpaw) January 14, 2021
It's less likely that Alyx will get it, at least initially, or without heavy DLSS, as that is already a visually taxing game at VR resolutions and ray tracing would likely make it unplayable at the frame rates required to make VR safe and comfortable. But the potential is there, and that's certainly exciting.
Development of the Source 2 engine began shortly after the release of Half-Life 2: Episode 2, but didn't see the first release until DotA 2, when it was ported from the original Source engine in 2015. the Robot Repair tech demo was next in 2016, followed by Artifact, DoTA Underlords, and Half-Life:Alyx in the years that followed. All of those games, particularly Alyx, look fantastic in their respective ways and genres, but ray tracing could make them something quite special indeed.