Portal RTX was released last week by NVIDIA’s Lightspeed Studios. This is the same team that performed Quake’s facelift. Portal DLC aims to bring the source engine back to life with advanced ray tracing options. However, the upgrades lack AMD support, especially if you’re a Linux user. This wouldn’t stop the Mesa3D team from upgrading the RADV driver (Radeon Vulkan) to allow the same or similar feel to Portal RTX.
The RADV Vulkan driver for AMD Linux users sees continued assistance for Portal RTX
Portal RTX, just like Quake RTX released before it, uses next-generation ray tracing technology in the game that adds shadows and lighting effects not seen in the original game and adds texture paths to give the game an almost completely new look. We recently reported how Lightspeed Studios added NVIDIA hints throughout the game, including QR codes that can be scanned to unlock more easter eggs.
For the Mesa RADV driver, a lot needs to be done to make the game playable, but initial support is there. But for owners of AMD Radeon graphics cards, the game has yet to fully support the hardware. Yesterday, the RADV and NIR fixes were merged into Mesa GitLab. Changes affect texture samples and incorrect processing. This hotfix comes with some glitches, as shown below.
Here are the fixes updated 2 days ago before the merge:
- 7b5ac0ae – radv /rt: Workaround for incorrect NOT_DEFERRED handling in Portal RTX
- 48ae92ce – radv/RT: radv_pipeline_key posted
- cdd68cba – radv / rt: pipeline key hash
- 7a994d92 – spirv: Add a debug option to force irregular texture sampling
- 9492b84a – radv: Add a driconf option to force irregular texture sampling
- 5751ae45 – radv: Force irregular texture sampling with NV Remix
Michael Larabelle of Phoronix states that this new integration follows a previous overhaul of UE4 (Unreal Engine 4) and Portal’s RTX ray tracing shaders that were built for Radeon Vulkan. Mesa 23.0 is expected to be released next quarter during 2023, and it is expected that by then, if not earlier, AMD Radeon GPU Linux gamers will have a chance to play the game through the open source platform.
News sources: Phoronix, Mesa GitLab