Portal with RTX is a free DLC for all Portal owners developed by NVIDIA Lightspeed Studios. Experience the critically acclaimed and award-winning Portal reimagined with ray tracing. Every frame of gameplay is upgraded with stunning full ray tracing, new, hand-crafted hi-res physically based textures, and new, enhanced high-poly models evocative of the originals, all in stunning 4K. In Portal with RTX, full ray tracing transforms each level, enabling light to bounce and be affected by the scene’s geometry and materials. Every light is ray-traced and casts shadows, global illumination indirect lighting naturally illuminates and darkens rooms, volumetric ray-traced lighting scatters through fog and smoke, and shadows are pixel perfect. Portal with RTX is compatible with all ray-tracing capable GPUs.

Post feature Report RSS RTX Remix Runtime Going Open Source
RTX Remix Compatible

The RTX Remix runtime, used to power Portal RTX, is going open source, permitting community contributors to create compatibility updates for future titles!

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In September of 2022, NVIDIA announced RTX Remix, a tool designed to intercept the visual layer of classic games and then allow for cutting-edge visual remasters of assets and lighting using the most advanced form of RTX yet, path tracing. Modders have already been looking into forcing the runtime into other games and achieving a homebrew implementation, but now, the Remix runtime is being open-sourced. Read on to learn what this means for the community and how you can participate!


Portal with RTX shipped in December of last year and demonstrated a total visual overhaul of the game, complete with modernised assets and fully simulated lighting. It was also a proof of concept for how RTX Remix could be leveraged by modders in the future to create their own remasters of classic titles - not only those games with pronounced modding support and dedicated scenes, but also older games that never got their shot at being moddable by fans.

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The RTX Remix app is not yet available to mod creators, but despite that, many modders have been working to implement patches onto other games using the existing Portal RTX run-time, targeting more Source engine titles like Half-Life 2, as well as working out rough compatibility with other games. Much of this experimentation has been done with limited tooling, though since Portal RTX’s release, more of this functionality has been opened up within the runtime. Now, the actual runtime itself is open source, with the possibility for competent developers to create compatibility patches for other games.

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The runtime is being hosted over on github, and being provided under a permissive MIT license. Chiefly, NVIDIA are hoping users will be creating their own compatibility patches for other games, bolstering the line-up of games that will be able to interact with RTX Remix on day one; following this goal, especially competent contributions and pull requests on the repository could lead to direct implementation into the runtime, following review and feedback from engineers. That means the community can take an active hand shaping what’s going to be possible with Remix, for which early access may be coming soon.

Screen Shot 2022 09 21 at 11 52

The full range of open sourced features include:

  • USD (Universal Scene Description) capture and replacement modules, which are responsible for capturing a game scene to USD, and replacing original game assets with modded game assets at runtime.
  • Bridge, which translates the renderer from a x86 to a x64 instruction set. This component uncaps the memory available for rendering.
  • Scene manager, which uses information coming through the D3D9 fixed function API to create a representation of the original scene, track game objects frame to frame, and set up the scene to be path traced.
  • The core path tracer, which includes the rendering loop, the materiral handling, and the game specific rendering features (ex: decals and particles), though not the component technologies that help it run like DLSS and RTXDI.

This is an exciting development in the possibilities that continue to open up with RTX Remix. Already, one of ModDB’s most celebrated mods is being remastered in conjunction with the RTX runtime and in collaboration with NVIDIA, and once official tooling becomes available, old games will become like new again as modders once again pick up the baton and keep iconic titles relevant into the modern day.

What games are you hoping to be made compatible with RTX Remix? Let us know in the comments down below, and don’t forget to add your mod to the site when the time comes!

Add your mod to the site here!

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The_Preacher
The_Preacher - - 820 comments

RTX Remix will be a game changer (pun intended).

Going open sourced ... will be even bigger game changer.

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The_Preacher
The_Preacher - - 820 comments

To note of... to not make a mistake and think this will be a "magic wand" like modding experience... it will still require tons of work, optimization and gradual coming to a maturity.

But already at release, you could call this almost as "universal graphic injector / universal draw call interceptor". But its even more than that, in one sense, and its an universal modding tool.

And like with every new shiny tech, it will take some time to get refined, but it will progress and evolve. Some folks will expect "magic" right out of the box, but thats not the case. Altough some work already on SWAT4 and Max Payne 1 shows absolutely promising results. And remember... this is officially, not yet fully out... and people are already making progress with it.

Im starting to think that modding fanbases in not so far future will be capable to make not just remasters, but true remakes fully on their own. AI advancements will also enable many tasks to be automatized further, as well.

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Kondiq
Kondiq - - 5 comments

Same goes for universal Unreal Engine (UE4 and UE5) VR injector UEVR. You'll be able to play almost any UE game in VR without any changes, but some will require heavy work to make motion controls work. Or at least 6DOF motion controls, because Praydog already figured out how to use blueprint system to make 3DOF controls work for any game:

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raynor009
raynor009 - - 102 comments

Meh I think many of us would've preferred a more refined tool, something akin to the GECK or similar to what they showed in the video. Maybe they realized this is too ambitious and releasing the code on GIT is their way of saying "knock yourselves out". Whatever happens, they will profit from this regardless.

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Kralich/David Author
Kralich/David - - 832 comments

The final tool is not out yet - this is basically enabling people to work out compatibility conflicts before the actual tool is out.

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Alpa47
Alpa47 - - 7 comments

I've being waiting for this. I can't wait to see the magic, like in SWBFII or GTA IV.

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SenisterDenister
SenisterDenister - - 129 comments

This is going to be so good in old games like Aliens vs Predator 1 and 2.

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Fyshtako
Fyshtako - - 32 comments

Damn, nice! Glad to see something this good being shared with the community openly.

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Anthony817
Anthony817 - - 2,771 comments

Excited to see how much further this can push the old Battlefield 2 Refractor 2 engine as far as lighting and memory allocation goes where we can run very HD assets with little impact to game performance. The fact it will allow games to use over 4gb memory is a game changer.

Also, I hope this makes reshade obsolete. Nothing worse than having pretty shaders that overlay a full game rendering the menus blurry. This natively modding the games in real time should mean far better graphical enhancements.

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sycspysycspy
sycspysycspy - - 67 comments

I tried a few games that I have installed on my PC, non of them seem to work at all. All the games I have tried is from early to mid 2000. Here's the list of the games I have tried: Delta force BHD, Ground Control 2, Command&Conquer; Zero Hour, Unreal 2, Warcraft 3 TFT and Rainbow 6 Reaven Shield.

P.S. Don't expect this tool would work on everything out of the box, it can only fit few very limited scenarios for now. This is an interesting tech and I hope it would get more attention and works on more games.

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