PC game modding is colossal - over 10 billion game mods are downloaded each year. Mods enhance graphics as faster GPUs are released, extend a game’s lifespan with new content, and expand their audience with total gameplay conversions.

With NVIDIA RTX Remix, we’re enabling modders to remaster their favorite classic games with full ray tracing, NVIDIA DLSS, NVIDIA Reflex, modern physically-based rendering (PBR) assets, and generative AI texture tools — one of many generative AI announcements made at CES.

Access to RTX Remix was previously limited to select early access modders, but starting January 22nd, any modder can remix a compatible, classic game thanks to the open beta release of the RTX Remix Application.

RTX Remix has already delivered stunning remasters in NVIDIA’s own Portal with RTX, and the modder-made Portal: Prelude RTX. Now, Orbifold Studios is using RTX Remix to develop Half-Life 2 RTX: An RTX Remix Project, a community remaster of one of the highest-rated games of all time. Check out this new Half-Life 2 RTX gameplay trailer, showcasing the latest updates to Ravenholm:

For more information on the project, and new 4K screenshots, keep reading

NVIDIA RTX Remix Open Beta Begins January 22nd

NVIDIA RTX Remix, built on NVIDIA Omniverse, is an end-to-end platform for remastering DirectX 8 and 9 games with fixed function pipelines, such as Call of Duty 2, Hitman 2: Silent Assassin, Garry's Mod, Freedom Fighters, Need for Speed Underground 2, and Vampire: The Masquerade – Bloodlines. Remix consists of a creator app for remastering assets, and a runtime for capturing original game assets and injecting remastered assets back into the game.

RTX Remix App

The RTX Remix app is your central UI for creating RTX mods of classic games. Easily import game captures, enhance assets, relight scenes with full ray traced lighting (also known as path-traced lighting), and review updates live in the viewport.

RTX Remix app features include:

  • RTX Remix’s ingestion pipeline, which converts a variety of file formats to Universal Scene Description (OpenUSD), making it easy to open and edit them in your favorite Omniverse-connected app, including RTX Remix itself.
  • Easy asset replacement. Upgrade models with new, high-poly replacements that rival the detail and fidelity of those found in modern games. RTX Remix features a free bank of high quality USD assets created by NVIDIA, ready to be used in your next mod. Import them into your mods as-is, or remix their properties using an Omniverse connected application of your choice, such as Blender or Adobe Substance.
  • Support for a variety of PBR material maps, including albedo, metallic, roughness, emissive, normal, subsurface scattering and height maps, which can leverage Parallax Occlusion Mapping (POM) to make texture surfaces realistically bumpy, for improved interplay with fully ray traced light and shadow.
  • Relighting with full ray tracing. Convert basic light sources into physically-accurate dynamic lights, capable of casting high-fidelity ray-traced shadows, illuminating scenery, and interacting with the Physically Based properties of enhanced textures. And insert new lights to transform the appearance of a scene even more.
  • Multiple views to help with your remaster. For example, use wireframe mode to see the polygonal detail of every asset, or a “white mode” to view lighting in neutral conditions.

Generative AI Texture Tools

One of the most time intensive parts of modding is updating every texture to modern gaming standards – that means building them at higher resolutions with a physically-based rendering (PBR) workflow, so the materials can react to ray-traced lighting.

Most mod teams lack the time to give attention to each and every asset, making AI invaluable. The solution: RTX Remix’s Generative AI Texture Tools that leverage Tensor Cores in GeForce RTX GPUs to analyze low resolution textures from classic games, and generate physically accurate materials including normal and roughness maps, before upscaling their resolution by up to 4X.

Original Textures on left, AI Enhanced Textures on right. Click here to view the comparison in 4K

With PBR, glass reflects the world with clear detail, while laminate wood flooring has rough, coarse reflections. And stone, though without visible reflections, is still capable of bouncing light and having an effect on the scene.

Original Textures on left, AI Enhanced Textures on right. Click here to view the comparison in 4K

AI-enhanced textures from RTX Remix are a huge upgrade over the simple color textures found in classic games, giving artists more time to turn their attention towards manually rebuilding hero assets that excite the imagination and define the visuals of a game.

Original Textures on left, AI Enhanced Textures on right. Click here to view the comparison in 4K

Reimagine Assets Via NVIDIA Omniverse-Connected Apps

RTX Remix is built on NVIDIA Omniverse, a development platform to connect complex 3D workflows, allowing you to move assets quickly between RTX Remix and popular 3D tools like Blender and Adobe Substance via Universal Scene Description (OpenUSD) framework.

This is a game changer for modders, who are accustomed to juggling unique file formats and proprietary tools for each game they are trying to mod, due to the unique nature of each game engine. A modder who made an impressive asset they want to use across five different games would need to convert that asset into five unique file formats, each with their own drawbacks, and use five proprietary tools to plug the asset into each game engine.

With RTX Remix and OpenUSD, modders have a single unified workflow that allows them to carry their favorite OpenUSD assets forward to a variety of titles, making it easy to remaster a diverse set of games with the same process.

RTX Remix Runtime

Every developer tweaks their work as they play and test, and with the RTX Remix runtime it’s even easier. The runtime makes your asset replacements, scene upgrades, and ray tracing improvements a reality, replacing content at playback and injecting RTX technologies, including full ray tracing, DLSS 3, and Reflex. Underneath the gorgeous exterior, your favorite game, with all of its timeless gameplay, remains intact.

Bring up the Remix runtime overlay in-game and you can make live changes to customize your experience. For example, add real-time fog to allow for beautiful volumetric lighting, or enable a mode where legacy assets are highlighted, allowing you to appreciate every asset that was replaced in a mod.

For the Open Beta, the updated Remix runtime has received several enhancements:

  • Off-camera lights are no longer culled, ensuring all ray-traced lighting is rendered at all times at the maximum distance, regardless of the camera or player’s orientation, enabling off-screen shadows and light to fill a scene.
  • Classic games sometimes used Terrain Baking to blend layers of textures together to create more realistic and detailed floor surfaces. Remix now supports this feature, enabling you to replace the classic textures with new hi-res ones, dramatically improving image quality.
  • Subsurface Scattering (SSS), the transmission, refraction and dissipation of light through layers of material is now supported on foliage, enabling light to permeate forest canopies and enhance thick sections of vegetation in games. Simply assign a SSS map to an asset in the RTX Remix Application and the runtime will render it properly.

Subsurface scattering allows light to pass through thin materials, like leaves or lamp shades - click here to load a fullscreen comparison

  • Parallax Occlusion Mapping (POM), allows height maps on textures to translate into bumps and protrusions that can cast shadows, making 2D textures look 3-dimensional.

Modders used POM in Half Life 2 RTX to make each brick of the cobblestone road protrude and self shadow - click here to load a 4K fullscreen comparison

Additionally, the Remix runtime is available as open source on GitHub, allowing the community to make modifications or submit changes to NVIDIA to bring into the main branch.

All of this technology will be released for free as part of the RTX Remix Open Beta on January 22nd. Head here to sign-up to be notified when it is released.

Mod developers should check out the RTX Remix Showcase Discord, where users have already been creating Remix mods, and experimenting with the runtime. Get advice, showcase your project, and help others remix their favorite classic games.

ModDB - Hosting RTX Remix Remasters

As we approach RTX Remix’s Open Beta coming January 22nd, ModDB will be adding a new RTX Remix section, making discovery, modding and sharing of classic game mods even easier. The site will feature:

  • A compatibility list to track which classic games the community has found work best with RTX Remix.
  • ‘RTX.conf’ configuration files and USD captures for compatible games. These make getting started on modding a game even faster.
  • 50GB mod upload size for RTX Mods - no other site allows you to upload mods as large.
  • Easy tags across the site to find RTX Mods and related news.

New Half-Life 2 RTX Trailer

Half-Life 2 RTX: An RTX Remix Project is being developed by four of Half-Life 2’s top mod teams, now working together under the banner of Orbifold Studios. Using the latest version of RTX Remix, the modders are rebuilding materials with PBR properties, adding extra geometric detail via Valve’s Hammer editor, and leveraging NVIDIA technologies including full ray tracing, DLSS 3.5, Reflex, and RTX IO to deliver a fantastic experience for GeForce RTX gamers.

Since the project’s announcement in August, Orbifold Studios has recruited new modders via the Half-Life 2 RTX: An RTX Remix Project website, and now boasts a team 65 modders strong. In the time since, the expanded team has been hard at work building enhanced assets and remixing the game’s beloved levels. In their new trailer, Orbifold is showcasing their latest work on Half-Life 2’s spooky Ravenholm, the zombie infested town that creeped players out back in 2004.

Click here to load a fullscreen 4K comparison

As with the Portal projects, almost every asset is being reconstructed in high fidelity, and full ray tracing is being leveraged to bring cutting-edge graphics to Half-Life 2.

Click here to load a fullscreen 4K comparison

In Ravenholm, average world textures have 8X the pixels, and are brought to life with Parallax Occlusion Mapping (POM) and PBR.

Click here to load a fullscreen 4K comparison

Monstrous creatures like the zombies feature almost 30X the geometric detail in Half-Life 2 RTX, going from 4,200 triangles to a staggering 75,590 triangles. Father Grigori, similarly, is now composed of 68,341 polygons. Weapons have been updated, with the Gravity Gun featuring 7X the textures, and 70X the polygonal detail. Now the materials of your weapon, the glass, metals and plastics, react to the world around you, catching light, shadows and color as you move.

Click here to load a fullscreen 4K comparison

Reload animations have been updated, and each time you fire your weapon, the muzzle flashes illuminate the darkest rooms. Orbifold Studios has even used Valve’s Hammer editor to rebuild the particles and explosions in Half-Life 2 to modern standards, which combined with full ray tracing means fire glows and swells, and explosions cause smoke to propagate through light, imbuing clouds with beams of color.

Using RTX Remix, the team has added realistic lighting and shadowing to each part of Ravenholm, greatly enhancing the moody, dimly lit streets, abandoned buildings, and ingenious traps set up by Father Grigori. See for yourself in the new Half-Life 2 RTX trailer:

To further enhance image quality, Half-Life 2 RTX features NVIDIA DLSS 3.5 with Ray Reconstruction. Ray Reconstruction replaces hand-tuned ray tracing denoisers with a new unified AI model, elevating the image quality of ray-traced effects and full ray tracing to new heights, further enhancing detail and realism.

In the trailer, DLSS 3.5 allows foliage to look more detailed, and shimmer less. It also makes fire, flashes of light, and shadows render more responsively. With DLSS 3.5, when you move through Ravenholm with your flashlight, every shadow you create will dynamically appear in the world and update in real-time with your movements.

For further updates about the project, stay tuned to the Half-Life 2 RTX: An RTX Remix Project website; if you’re a modder, you can also sign up to join the project.

Download The RTX Remix Beta On January 22nd

If you want to make your own ray-traced mod for a classic game, the NVIDIA RTX Remix Open Beta begins January 22nd. Head here to sign up to be notified of its immediate release. Check out ModDB to find the latest RTX Remix mods and visit NVIDIA Studio to learn more about RTX-accelerated software, like Omniverse, Adobe Substance and Blender.

For other RTX announcements from CES 2024, check out GeForce.com.