RTX Remix?
Sometimes people say that today’s games don’t measure up to the old ones and don’t offer much besides visuals. But what if modern visuals could be added to classic games that are even twenty years old? NVIDIA’s RTX Remix technology (or software) is supposed to do just that, making it relatively easy to add better graphics to even very old games using a mod – including raytracing effects and things like DLSS or DLAA. Let’s see how it works.
Disclaimer: This article was commissioned by NVIDIA and is paid for. However, the company did not interfere with its content in any way, and the only requirement was to test a few old games with new technologies in RTX Remix.
What is RTX Remix
RTX Remix is a technology that NVIDIA unveiled in September 2022 at the same time that GeForce RTX 4000 graphics cards were coming out. It is a tool and runtime for creating modifications and (usually) fan-made “remasters” of older games and enhancing them with higher quality and more modern graphics, including bleeding-edge effects such as ray tracing.
Modifying games, which often takes them in unexpected directions, is something that has been done before by various enthusiasts. But RTX Remix should make such modding massively easier, while expanding its possibilities. We can already see that in action, as raytracing “RTX” game mod projects are springing up in numbers that probably wouldn’t even be conceivable without RTX Remix.
The basic problem with modding games is that developers cannot usually work with the source code of a game (with exceptions like Doom, Quake) and add new functionality to the program, which precludes adding raytracing code to existing games. Furthermore, older titles usually rely on outdated and limited APIs, while ray tracing in games requires the use of DirectX 12 or Vulkan. Not to mention that most of these will be 32-bit programs, so they don’t support the amount of RAM footprint that the modernized visuals would require. In many cases, however, almost any modifications, even simple ones, face major hurdles because there are no tools available to create the content for the game.
A universal way to “hijack” and change game visuals
RTX Remix gets around this in an interesting way. Modifications are not created by conventional game files editing, but in an indirect way. RTX Remix uses a special runtime that is inserted (injected) into the game’s rendering process, which intercepts all the calls to the graphics driver that the game uses to create the game’s visuals and scene as it runs.
First of all, the runtime analyzes the game and compiles information about how the game scenes are created, what objects are used in them (their polygon models) and what textures they have, as well as the lighting and camera angles of the game. Later, a similar process with the RTX Remix runtime injected is used to modify the objects directly in the running game.
Level editor and object catalogue for any game
The data obtained from this “real-world” analysis of the game scene is then used by NVIDIA RTX Remix to rebuild the scene outside of the game and outside its original engine, essentially replacing the development environment (level editor) and its viewport. It shows a preview of the scene and allows you to view and modify it. It provides a catalog of objects and effects found in the scene, including their modifications.
This is where the advanced modding and graphics enhancement options begin. RTX Remix converts the objects (and the entire scene made up of them) that have been extracted from the game in this way (basically, you could say they have been observed and “scanned”) into the USD (Universal Scene Description) format. And in this format, you can start working on enhancing and adjusting them into better versions that will eventually be wrapped into the final mod.
The scene elements don’t always (and probably usually won’t always) automatically transfer between the game and RTX Remix reworked version with 100% correctness. It is expected that the modder will still have to do their own work, for example, adjusting the placement or behavior of some objects that don’t work correctly with the conversion, and dealing with any issues that may arise when importing and exporting and hooking the RTX Remix runtime into the game. The functioning of this technology is quite a complex process, and the games themselves as well are a complex apparatus with various peculiarities and atypical behaviors that can manifest themselves in unexpected bugs and incompatibilities when the game is interfered with in ways that the original developers were not expecting.
Tools require GeForce RTX, these emerging mods do not
RTX Remix’s technical solution is plugged into NVIDIA Omniverse technology, which provides a collaborative environment for working with 3D graphics and linking with other important tools (3ds Max, Autodesk May, Blender, Unreal Engine, and so on) where a modder can, for example, create new and improved models. At the same time, it allows collaboration with many other enthusiasts, making it easier for modders to work as a team.
RTX Remix also has its limitations. The development part can only be used on NVIDIA GeForce RTX graphics cards (or professional NVIDIA RTX GPUs). The RTX Remix runtime tools and Omniverse tools are needed to develop RTX Remix-based modifications, so the modder must have an NVIDIA graphics card (at least for Omniverse).
However, the modification itself is no longer limited in this way. It also needs to have a packaged runtime (which is open source, by the way) that intercepts the original game calls and replaces them with modified calls and new game objects. This part of the process should already work on any GPU (or at least in theory) that has the necessary features, i.e. support for DirectX 12 Ultimate and ray tracing acceleration.
However, one problem for use on other graphics cards is that RTX Remix only adds DLSS upscaling support (no XeSS or FSR), so you’ll only be able to use native resolution on competitor graphics cards, which the cards may not have the performance for as RTX Remix mods using full ray tracing are highly demanding. Users also report poor performance with specific mods (poor FPS even at low resolutions like 800×600), so it’s questionable how well the RTX Remix runtime works on non-NVIDIA graphics cards, or at least at the moment.
Which games can (and cannot) use RTX Remix: Technical limitations
Runtime RTX Remix currently supports games running on top of the DirectX 8 and DirectX 9.0 to 9.0b APIs. Games using DirectX 7 and older are not directly supported. At least in some cases, however, RTX Remix should be able to be used on them, but only if they work with a wrapper that converts them to DirectX 9. The problem is games requiring DirectX 9.0c, where RTX Remix does not work easily, unlike games using DirectX 9.0b and older. Games using OpenGL or non-PC games do not work with RTX Remix (theoretically they could with a working wrapper that converts their calls to DirectX). RTX Remix also cannot be used with games using DirectX 10 and newer.
An important restriction is that the game must use the so-called fixed-function pipeline, the standard way of working with geometry and textures in older games (usually, you can spot such games based on whether they support running on GeForce 2 graphics cards, which are the last generation with without shader support). Later games started to replace fixed-function rendering with a model using primarily shaders and shader-defined objects (such a game may typically specify a GeForce 3 as the minimum requirement). Objects defined by shaders do not work in RTX Remix. It’s theoretically possible that support for such newer games will eventually appear in RTX Remix at some point, but it’s a much more challenging task that is not yet planned to be implemented. Otherwise, the technology will still need further development before it is perfect in fixed-function games, which is a priority for now, before work on other ambitious goals can be started.
Exporting from RTX Remix creates a modification that should (at least in theory, in practice you may encounter bugs and individual incompatibilities) be very easy to use – just copy it to the original game folder and run it. The RTX Remix runtime already takes care of converting the game calls to the Vulkan API, so even some games quarter-century old now can be drawn via a modern rendering pipeline. And at the same time, all the old objects in the scenes you’re traversing in the game will be replaced with new, improved ones.
And yet you’re still playing the original game, which is basically unaware of these modifications. And that’s important, because all the original mods you’ve accumulated over the years will work in it, as well as the original save positions, cheats, character editors, and so on. However, RTX Remix does use DLL injection of code into the program. Thus, this modification is likely to be detected as cheating by anti-cheat software, which prevents the use of such mods in multiplayer games (because you would likely get promptly banned).
The fact that RTX Remix brings the game rendering onto modern graphics API opens up the possibility of using new features like DLSS, including Frame Generation, and ray tracing (but also Ray Reconstruction or Reflex technology). This is done in real time directly while playing and the original game program is not affected. Because of this, RTX Remix can replace visuals even in a game for which there is no documentation at all, no development tools or tools to work with, and so on.
What RTX Remix makes possible
If the goal of a game modification is to update the game’s visuals overall, RTX Remix allows for a total replacement of the game’s models and textures by capturing them from the game. Textures can be given better resolution (AI upscaling tools can be used to do this) or they can be replaced entirely with new, hand-made ones. Even models can be completely replaced with new ones.
RTX Remix can engage AI here, so manual adjustments are far from the only way to go. In addition to AI texture upscaling, which is something you’ve may have already seen in many existing game mods even before RTX Remix, it can also use AI analysis to estimate the physical properties of the materials (for physically-based rendering) of a game scene and add them to individual objects. This can significantly improve the realism and quality of the visuals. It is also possible to add normal maps and reflectivity information to existing textures, which will then allow game lighting to be added using ray tracing rendering, including full Path Tracing.
RTX Remix also allows you to add newly designed lighting to the scene, which can then be ray traced in-game to completely change the character of your games. RTX Remix also has a special “Light” mode for this purpose, where lighting is easier to adjust.
Lighting makes a massive difference in game visuals, and in most older titles it’s quite primitive (and of course very unrealistic). With realistic light sources and handling the diffusing and fading of their glow in the environment, with reflections and shadows, the scene can take on a whole different level of realism. However, this changes the visuals a lot, which can often make scene significantly darker; without manual adjustments, you may even have trouble seeing anything in the scenes, as the original level design didn’t account for the behavior of light at all. Modifications therefore often add a flashlight tool to the game, which you can use to help yourself in situations where it’s too dark.
The nature of the games is obviously changed by these modifications (and with lighting this is very noticeable), so the question is whether this is desirable. A game as a whole is essentially a work of art, and its original visuals, including how they were influenced by the technological limitations of the time, form its character. That’s probably why RTX Remix or other remakes shouldn’t be treated as replacements for the original. But as long as we don’t let the old game disappear (which, fortunately, isn’t facilitated the way RTX Remix works) and we understand that we are playing an alternative, “remade” or upgraded version of the game, these modifications certainly have their place as can give the game a new appeal.
The article continues with further chapters.
⠀⠀
Sometimes people say that today’s games don’t measure up to the old ones and don’t offer much besides visuals. But what if modern visuals could be added to classic games that are even twenty years old? NVIDIA’s RTX Remix technology (or software) is supposed to do just that, making it relatively easy to add better graphics to even very old games using a mod – including raytracing effects and things like DLSS or DLAA. Let’s see how it works.
How to get ray tracing working in old games
Open Beta of RTX Remix and sources
RTX Remix is currently in beta and is already publicly available. You can download it here via the NVIDIA Omniverse tool, which you can then log into with your NVIDIA account and install the RTX Remix app from there. The RTX Remix runtime has a repository on Github.
NVIDIA Omniverse
Omniverse is a tool for collaboration of teams working with 3D graphics or CAD/CAM solutions, it can be used for example for organizing product development across continents and similar complex tasks, for creating digital twins of production plants or other objects, for industrial visualization, or for working with visual effects, as it supports integration with many important graphic tools and other software and applications. At the same time, Omniverse is also an SDK enabling the creation of new software with technologies such as raytracing graphics rendering and DLSS.
However, Omniverse can also serve as a simple app store-style platform for obtaining such applications, and the RTX Remix software is also distributed in this way, it can be easily downloaded via Omniverse after registering and logging in with an NVIDIA account (you don’t need a 3D headset for this, of course).
Installing RTX Remix from Omniverse is easy and straightforward, just be prepared for a relatively larger download which may take a while on a slow connection. The RTX Remix app obtained through Omniverse will allow you to start modding that game you get your eye on. It allows you to run it with an embedded (injected) RTX Remix runtime in order to analyze and catalogue the scene and objects, and work with the project files (rtx.conf profile for the game).
You can also use an rtx.conf profile that someone has already generated for a particular game and open it in RTX Remix mode for yourself.
The integration of RTX Remix into the entire NVIDIA Omniverse ecosystem is important because developers can use all of the in graphics and modelling tools and resources that support Omniverse interfacing, when modding games. And the collaborative features can then be used by developers to work together on modding and to pass on objects and components in progress. This was already demonstrated at the time RTX Remix was announced as the first demo showing a remastered scene from the The Elder Scrolls III: Morrowind game was created by a team working through Omniverse.
Mods: Big official projects and upcoming community remasters
Portal with RTX
In 2022, along with the RTX Remix tool and technology, NVIDIA also announced Portal with RTX, a remake of the iconic Portal game that was created using the RTX Remix tool and officially sponsored by NVIDIA (it was created by NVIDIA’s very own Lightspeed Studios).
Portal with RTX uses full ray tracing (i.e. they are not used just for select effects, but for rendering the entire scene) and all the new NVIDIA technologies: DLSS 3 upscaling, later also DLSS 3.5 with Ray Reconstruction, frame generation, and it has built-in support for Reflex technology to reduce latency. The game runs via the RTX Remix runtime on top of the Vulkan API (in 64-bit mode).
Portal with RTX has not only had ray tracing “added” to it, it has also seen extensive improvements to the game’s components at the model and texture level. Textures have physical characteristics that allow for realistic reflections and scattering of light and shadows, as well as increased resolution. The models are also more realistic with a high polygon count and new details, but the team working on them has kept their original silhouettes, so it’s a subtle change that doesn’t disturb the original character of the game.
Thanks to full ray tracing, the game has realistic lighting (including ray-traced volumetric lighting) as well as the associated shadow rendition, which should be fully realistic without tricks or simplifications. NVIDIA RTX Direct Illumination (RTXDI) and NVIDIA Reservoir Spatio Temporal Importance Resampling Global Illumination (ReSTIR GI) technologies are used, which allow games to use more direct and indirect light sources than what was viable before.
The original game had limited lighting using spot lights, but in Portal with RTX this is reworked and the game is redesigned with more light sources of different types and intensities (including the famous companion cube, for example).
As you’ll see in the screenshots, this significantly changes (and improves) the face of the game. Fans will be pleased to know that light and shadows travel and reflect even through all off the iconic portals in the game thanks to this. The implementation of ray tracing is more advanced than in Quake II RTX or Minecraft with RTX, with new techniques employed. Rays are reflected up to four times instead of just once. The demands on hardware are expectedly higher for this reasons, so DLSS and Frame Generation are important for playability on today’s GPUs.
Portal: Prelude RTX
Last year, NVIDIA added another part in the form of Portal: Prelude RTX. It’s a release that adds better visuals and full raytracing to the most popular mod of the original Portal, which is called Portal: Prelude and dates back to 2008. Prelude is an unofficial prequel to Portal with 19 levels by Nicolas Grevet (Nyk0018) and other authors.
Portal: Prelude RTX also uses full ray tracing with realistic shadows and lighting that has been manually redesigned. New higher quality models and textures with physical properties are used here as well, allowing for realistic reflections, mirror image effects and light scattering.
To improve performance, DLSS 3.5 support has again been integrated, including Ray Reconstruction (Portal: Prelude RTX was the first of the remakes to premiere the feature) and Frame Generation, as well as Reflex for improved latency. But the game also uses RTX IO, so it can take advantage of the highest-performance NVMe SSDs for faster texture loading with less load on the CPU, while also reducing the space taken up by the game on the hard drive. RTX IO is always active, no need to turn it on separately.
This mod again requires you to have the original Portal in your Steam library, after which you can get it for free. You can find it here.
Portal with RTX and Portal: Prelude RTX: future potential in mature form
Created directly with official support and with sufficient resources and development time, these modifications are now the best demonstration of what RTX Remix technology offers and enables. This makes them technological demonstrators and a kind of reference or benchmark of what can be achieved with RTX Remix.
And at the same time, these games are fully mature for consumption, so if you’re interested in the visual qualities of ray tracing, they’re the perfect choice for trying it out. Other modifications, which are created by a community of enthusiasts on their own, haven’t had a chance to get that far in the limited time available, so they’re more of a future potential. So if you want to try out what RTX Remix can do, the ideal place to start is with Portal with RTX and Portal: Prelude RTX.
Half-Life II RTX is also coming
Portal: Prelude RTX won’t be the last official remake NVIDIA will embark on, though. Last summer, the company announced the Half-Life 2 RTX project, which will be a similar remastered version of the game with full ray tracing, new textures and more detailed models, and support for new technologies. Again, virtually all of the game’s assets are to be improved.
The game is now in development under the Orbifold Studios banner, which is supposed to be a collaboration of four of the best modders for Half-Life II, so the modding community will be involved this time. On NVIDIA’s website, you can already see some previews of the game’s redesigned environments, which show that the game will be transformed quite dramatically, with some models of machines, computers and other props recreated from the ground up in modern detail.
It is not yet known when this remastered Half-Life II RTX game will be released.
Max Payne RTX ON Demo
The modification of this well-known game is also not yet finished, but it should reportedly be one of the more successful and relatively complete demonstrations, and is probably the furthest along of the fan projects in demonstrating the capabilities of RTX Remix technology. Several enthusiasts are working on it, and the goal is to make a large elaborate modification of the game. You can find it here.
The modification has to be installed on top of an existing installation of the full version of May Payne (a demo is not enough), but the process is a bit more complicated. You need to download the RTX Remix files using this downloader, copy them from the created folder to the Max Payne folder, then install Microsoft’s DirectX 9c runtime into the Max Payne folder and then a community patchset for the game and when using new processors, including AMD Ryzens, this patch fixing JPEG decoding in the game is required.
The developers state that the game should not be installed in Program Files x86, but somewhere else on the drive with unrestricted access (so that Windows don’t interfere trying to protect the folder from unauthorized write access). It is also recommended to removesecondary monitors. In case of problems, using the -skipstartup option, installing Visual C++ Redistributable, and also running in windowed mode instead of full screen (or disabling full screen optimizations and running the game as an administrator via Windows compatibility mode) can further help.
The original Tomb Raider (Open Lara RTX: Reimagined Realms)
Another modification that has surfaced is a remake of the first game in the Tomb Raider series, created by Aureate Games. It is called Open Lara RTX: Reimagined Realms, as it is a fork of the Open Lara Project mod. The original Tomb Raider is a game running under DOS, so RTX Remix could not be used on it directly.
This mod adds full ray tracing (path tracing) to the game, but like other similar projects it is not yet complete. You can download the demo, however, in which the first two levels are remixed. In addition to ray tracing and new lighting, the game also has some new textures and models (such as enemy animal models).
This mod can be downloaded from here, and as a baseline you need to own and have installed the original game from either Steam or GOG (but perhaps the original game data folder from a CD should work as well). It has a very user-friendly installer that even finds the folder with the installed game itself, and in this case the installation should be really easy (the RTX Remix files are already included). Indeed, on our test PC with a GeForce RTX 4080 Super, the installer worked flawlessly on the first try and basically just took a few clicks.
We had a different problem, ironically: While the mod was running fine, the original game failed to launch. The GOG distributed game uses DOSbox and stubbornly kept crashing despite our efforts, both in standard mode using the wrapper translating the original acceleration via 3Dfx Glide and with software rendering. We were not able to resolve the issue in the time available, sadly.
Grand Theft Auto: San Andreas
The popular GTA V won’t be able to be remixed due to RTX Remix limitations allowing only DirectX 9 and DirectX 8 games, but one very popular modification target could be Grand Theft Auto: San Andreas originally from 2004. The GTASA RTX Remix Project mod is in the works, which can be found on GitHub.
However, if you want to see the results in the current state of this modification, you will face a rather challenging installation. As always, you’ll need to have the original base game, ideally downgraded to version 1.0, furthermore you need manually downloaded RTX Remix files. But the mod files themselves are distributed via GitHub, so you’ll need to clone the repository with a tool (such as GitHub for desktop) and manually copy the files. After that, it is still recommended to install a number of other mods and patches for stable operation.
Therefore, after we struggled with a not so easy process with previous games, we didn’t test this mod for time reasons.
Greater selection
However, a larger number of these modifications are already in the works. A “showcase” catalogue of games that someone has plans to modify or at least experimented with can be found on the RTX Remix Discord here (it’s probably likely that some of these projects will be abandoned before completion, but on the other hand there may be others competing projects or other enthusiasts dealing with yet other games).
On ModDB you can also find a list of mods that are already available for download in some demo version or are in the process of being modified, or a list of RTX Remix compatible or semi-compatible games if you want to experiment with the development side of the thing.
Our experience
Most of the unofficial mods (if not all, since open beta access only started this January) for RTX Remix are not finished and you may encounter various issues when installing them and trying to get them running. For example, some reports say you are likely to run into problems if you use a laptop or desktop with both integrated and dedicated GPUs (and a hybrid graphics card). Users also report that their games sometimes start running only after uninstalling the OpenCL, OpenGL, and Vulkan Compatibility Pack, which you can have installed in Windows 11 (you can find it in the Microsoft Store, not in the classic list of installed programs and components). There can also be problems on computers with multiple monitors.
Modifications probably only see limited testing and debugging currently, so successful installation and launch is not a guaranteed thing. For example, we couldn’t get Open Lara RTX: Reimagined Realms to run on a second PC with a Radeon graphics card and Windows 11 (it’s hard to tell if it was a problem with that PC or the mod, but after launching the program remained stuck with no further response). But as we mentioned, on the main test PC this modification ran perfectly and installation was easy and without complications (which is far from the case with the other mods we tried).
With the Max Payne mod, we were almost lucky, but ultimately ended up empty-handed. We managed to get it up and running in shape sufficient at least for the purposes of performance testing after a bit of tinkering, but the visuals were flawed with a faulty final color rendering. Apparently all the rendering of objects and scenes was otherwise fine except for the output on the monitor. Because of this error, however, we could not use the mod for image quality comparisons.
It must be said, however, that for many people these modifications work out of the box, so don’t take away too much pessimism from that. Remember that open beta access for RTX Remix only started this January, so we are only at the beginning stage of community projects creating RTX modifications. In the future their demos will definitely be more stable and easier to use, the RTX Remix runtime itself will of course undergo development, and the sophistication of the remastered content itself will of course only be fully appreciated in time.
But you don’t have to worry about such pains with the official Portal mods (Portal with RTX, Portal: Prelude RTX) and the future Half-Life II mod, because they are developed and distributed by a professional team of many heads, unlike mods that are made by enthusiasts who don’t have a surplus of human resources. This of course will also be reflected in the high quality visuals, new models and textures that have been created for these games.
The Portal games can thus serve as an ideal demonstration of what can be achieved with RTX Remix technology, while the unofficial modifications often produced by single dedicated enthusiasts will be more about the skills and time of the creators.
⠀⠀⠀⠀⠀
Sometimes people say that today’s games don’t measure up to the old ones and don’t offer much besides visuals. But what if modern visuals could be added to classic games that are even twenty years old? NVIDIA’s RTX Remix technology (or software) is supposed to do just that, making it relatively easy to add better graphics to even very old games using a mod – including raytracing effects and things like DLSS or DLAA. Let’s see how it works.
Visual analysis
Original Portal vs. Portal with RTX
The very first scene from Portal using shows what a difference remixing to ray tracing graphics makes in an old game, and we’re not just talking about the visual quality of the detail, but rather the overall different character of the scene that path tracing/ray tracing creates. On the left you have the original Portal, on the right you have Portal with RTX (native resolution, without upscaling), with ray tracing. The comparison is made with NVIDIA’s ICAT tool.
Scene 1
The fundamental problem with traditional graphics, at least in these older games, is how the limited lighting simulation flattens the scene. Basically, there’s no sharp light, no darkness, and no sharp shadows. The darkest part under the cubicle is kind of grayed out and bright due to the small dynamic range. On the other hand, the light forms a kind of visible “ether” spreading from the lamp, although in the practical world it would not look like that. Because this illumination is spilt over a large part of the scene without contrast, the impression that the light is really bright is actully lost.
The result is more of a fog or haze. This fog, reminiscent of a view of a distant horizon in natural exterior, gives the game an unnatural look overall, but one that you wouldn’t find too noticeable if you were used to such games back in those days. But it comes out very clearly when you compare the image to the remixed version.
In Portal with RTX, the whole scene is free of this haze, and you can clearly see into the glassed-in area in the foreground, and the office section behind the glass in the back at the top. In a space with artificial lighting of this nature, the environment should definitely look more like this. The illuminating light effect and reflections of the open portal, which are missing in the original, are nice too.
Scene 2
That difference between the milky character of the light (left) and the contrasted raytracing lighting (right) is also present in the next scene. The raytracing technology adds portal reflections to the glass that are absent in the original.
Also note the difference in material on the floor and walls. This is texture replacement with RTX Remix in practice, it’s not just upscaled or using a higher resolution, instead the texture was replaced with a different graphical asset based on some stylistic choice of the modders. Again, we see the effect where the glass is somewhat bluish in the original game, adding a haze that the remixed version doesn’t carry over (one wonders to what extent this was the intention in the original). On the other hand, the new technology adds the ability for the glass to distort the image based on its material nature – note how the horizontal stripes on the glass break the shape of the portal behind it with light refraction effects.
Scene 3
The third scene is again transformed due to the texture replacement, but especially by the lighting, where the original (left) is perhaps quite overbrightened, although it is up to question whether the light in the remixed version (right) isn’t a bit too dim in turn. The strange cast shadows stretching horizontally across the walls and floor have disappeared in the raytraced version, but instead there are now properly cast real shadows from the cage in the corner and the camera or sensor on the wall. The latter unnaturally stands out against the light wall in the original version.
But raytracing makes a big difference on objects. The original doesn’t use illumination on the inside of the cubes, and the red light on the mechanism that drops them is also pretty unnatural. The biggest difference though is the series of lights on the ground, which in the original look like they’re painted on, whereas in the remixed ray-traced version you believe they’re glowing.
In the corridor passage you can notice the differently designed lighting at the end of it. This is again one of the things where modifications made with RTX Remix can make stylistic changes. Old games don’t have lighting that is very complex (much less based on the physical workings of its sources), which mods not only can, but in fact often must address and retouch the lighting design somehow.
Scene 4
In the final screenthos you can see how the presentation of the material changes with ray tracing (right). The original visual (left) couldn’t create the impression of things gleaming that ray tracing simulates quite nicely – see especially the cube-mosaic material on the sides of the foreground passage.
However, the light also reflects diffusely off the floor, which, along with the way the light is cast from a distant bright room, creates a much more natural feel and improves realism. It also allows you to perceive the perspective and distance of the opposite wall better. The original Portal cannot render the light and shadow that is created in a scene in this way.
The original also again suffers from that flattened rendering of light levels in the scene, whereas the remix has a more dynamic composition of light and dim or dark parts.
You can also notice the appearance of the metal pyramids above the passage in the foreground, or the added grilles on the doors (again, replacing the asset instead of just improving it).
Tomb Raider with RTX (Open Lara RTX: Reimagined Realms)
With Portal, we said that the realistic behavior of light and shadow makes a big difference in how natural a scene feels and how immersive it can be. Tomb Raider is probably an even better demonstration of this, as those light levels are even more primitive and flattened in the original. While you won’t lose your orientation in space in Portal, even though the nature of its original visuals already already has a bit of that feel, in old games like Tomb Raider, for example, that effect is already considerable for me.
In the RTX Remix modification, the environment is completely different. Using path tracing to render this game does dramatically change the look of virtually all the scenes, and leads to darkness in a lot of places that has to be dealt with by that flashlight tool we were mentioned in the previous chapters, but the perception of space is much better. You are also more likely to notice various niches, bends or openings that might not have been very noticeable in the original version (it is of course possible that this reduces the difficulty of puzzles where the authors may have relied on this).
The lighting added in front of the character that you see here is the flashlight feature. This is a tool that many mods use to overcome the fact that while the original game had uniform visibility due to technical limitations, the addition of realistic lighting by RTX Remix often causes nothing to be visible in the game environment. However, this also corresponds to how the environment should realistically work. Ideally you would want the flashlight to be held directly by the character, but that would already require modifying the game’s program and is beyond what RTX Remix can do (however, with Open Lara RTX it could probably be done, since it is a rewrite and replacement of the original game code).
Here you can see quite well how working with lighting will give you better grasp of the depth of the scene and improve your orientation. But you’re also more likely to see the various attacking vermin in this game, which you can often notice too late in the original, unless you are familiar with the game.
There’s something very interesting about the RTX Remix mod of Tomb Raider that might not be so visible in the final form, if the author proceeds with major replacement of in-game assets with brand new ones. If you click through our screenshots, you’ll see that the original low-resolution textures are still used, which are more of a kind of pixelized impressionism than a realistic representation of objects and materials. This looks, let’s face it, quite bad in the original game.
But it’s remarkable how much the impression changes when the same thing is rendered with realistic lighting and shadows. The transitions this creates mercifully hide extreme texture imperfections and even extremely angular models (look at how your hands look with the guns drawn, for example), at least in interior and dark scenes. It’s possible that after several hours of playing, one gets used to this and starts to see those imperfections again.
This image shows how incredibly primitive the original game’s environment is from today’s perspective. The shadows and light rendered by ray tracing can help the final look a lot, though. It works better when the scene is dark and there’s a local light source throwing shadows like this.
In strong daylight and outdoors, ray tracing probably wouldn’t salvage the primitive models and textures as much, as is somewhat hinted in the following image (it would help if there were more different objects and shapes in the scene to cast shadows). The original Tomb Raider is a game set in an interior space, though sometimes a view of the outside environment is simulated.
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Sometimes people say that today’s games don’t measure up to the old ones and don’t offer much besides visuals. But what if modern visuals could be added to classic games that are even twenty years old? NVIDIA’s RTX Remix technology (or software) is supposed to do just that, making it relatively easy to add better graphics to even very old games using a mod – including raytracing effects and things like DLSS or DLAA. Let’s see how it works.
How we tested
The measurements were performed in the same conditions as our standard graphics card tests. This means with active system cooling with strictly controlled air temperature (21–21.3°C) at the wind tunnel intake. This enforces repeatable accuracy of the monitored measurements.
On a Gigabyte Aorus RTX 4080 Super Master 16G graphics card (with the OC BIOS) we measured gaming performance in Portal with RTX, Max Payne and Tomb Raider (more precisely, the Open Lara RTX: Reimagined Realms mod) in 2160p, 1440p and 1080p using NVIDIA DLSS 2.x technologies (Quality, Balanced, Performance and Ultra Performance) and DLSS Frame Generation. This gives an idea of what the game’s FPS are after their application, as well as what they look like when this feature is turned off (in a mode without upscaling and with DLSS Quality).
Of the various DLSS 3.5 technologies, Portal with RTX also supports Ray Reconstruction, which is always enabled when possible. Unmodified original games are on default settings (Portal), which are usually the highest possible graphical settings without Anti-Aliasing or with settings recommended by their modders. For example, in Max Payne with textures on “medium” or hero shadows on “low”. This is for consistency with the general settings for the modded game, as image errors occur in the modded game if these settings are not respected. In Open Lara RTX, the general settings are “low” and most of the options are not changeable, with no user adjusting offered.
Details of the exact graphics settings can be found in the following sections next to the results of each game. All test profiles have been repeated three times for maximum accuracy and the arithmetic average of the runs is shown in the graphs.
The processor of the test build is the Intel Core i9-13900K without power limits, cooled using the Noctua NH-U14S, and coupled with DDR5 Patriot Viper Venom (2× 16 GB, 6000 MHz/CL36) memory. The foundation is the Asus ROG Strix Z790-A Gaming WiFi II motherboard (BIOS v0801) with ReSizable BAR enabled.
Graphics drivers are NVIDIA GeForce 552.22 Game Ready. We use the BeQuiet! Dark Power Pro 12 (1200 W) PSU and, for for the sake of completeness: the SSDs used are the Patriot Viper VP4100 1 TB (system storage) and the Patriot VPN100 2 TB. The operating system is Windows 10 (22H2).
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Sometimes people say that today’s games don’t measure up to the old ones and don’t offer much besides visuals. But what if modern visuals could be added to classic games that are even twenty years old? NVIDIA’s RTX Remix technology (or software) is supposed to do just that, making it relatively easy to add better graphics to even very old games using a mod – including raytracing effects and things like DLSS or DLAA. Let’s see how it works.
Gaming performance in Portal (with RTX)
Test scene: Chapter 1, the route from the initial portal through the corridor, to the platform which opens the gate to the next level.
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Sometimes people say that today’s games don’t measure up to the old ones and don’t offer much besides visuals. But what if modern visuals could be added to classic games that are even twenty years old? NVIDIA’s RTX Remix technology (or software) is supposed to do just that, making it relatively easy to add better graphics to even very old games using a mod – including raytracing effects and things like DLSS or DLAA. Let’s see how it works.
Gaming performance in Max Payne (with RTX)
Test scene: Suburban transport. After descending the stairs, we come along the track to the toilet to the murdered policeman.
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Sometimes people say that today’s games don’t measure up to the old ones and don’t offer much besides visuals. But what if modern visuals could be added to classic games that are even twenty years old? NVIDIA’s RTX Remix technology (or software) is supposed to do just that, making it relatively easy to add better graphics to even very old games using a mod – including raytracing effects and things like DLSS or DLAA. Let’s see how it works.
Gaming performance in Tomb Raider with RTX
Test scene: At the beginning of the game, Lara runs in a long straight line through traps until she hits a stone wall.
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Sometimes people say that today’s games don’t measure up to the old ones and don’t offer much besides visuals. But what if modern visuals could be added to classic games that are even twenty years old? NVIDIA’s RTX Remix technology (or software) is supposed to do just that, making it relatively easy to add better graphics to even very old games using a mod – including raytracing effects and things like DLSS or DLAA. Let’s see how it works.
Conclusion
It’s probably not entirely appropriate to judge the quality of mods that are mostly in their infancy at this point. However the effect that RTX Remix is able to add to the game is still very promising.
But the technology itself is certainly remarkable and it’s a good idea, especially as we can already see that it can and does work in practice and can be of great benefit for enthusiast remasters or remixes of games. There are a number of games whose authors or owners will probably never give us any official facelifts and improvements, or games for which even the source code or assets such as models and textures have been lost, making that impossible barring a full rework from scratch.
Remix allows you to make modifications to the game practically from the outside without any need to have the original source materials and development tools available, and that’s a powerful tool. It has its limitations, as shown by the flashlight trick the games use, for example. It’s part of the RTX Remix runtime and not the original game, so while you can turn it on with a hotkey, it adds light to your rendered game that comes out of nowhere and isn’t integrated in any way. Getting your in-game avatar to actually pull out a flashlight and have it shown probably isn’t within the power of RTX Remix (though for FPS games where you just need a single object that doesn’t need to be connected or interact with anything else, such look could probably be successfully faked.
In any case, there are reasons to look forward to what will come of this venture. Hopefully development of mods will continue successfully and users creating modifications will have a make a good use of it. Perhaps there will even be madmen who would try to remix the giant open-world game that is Morrowind as in the demo that was shown during the technology’s debut.
Is the looks all that is being improved? Yes, but that’s not a small thing
Going back to that sentiment that modern games often don’t have much to them besides great expensive visuals, while they are empty and soulless behind them — even when comparing Portal to Portal with RTX, it’s tempting to remark that all that Remix RTX brings is just nicer outward appearance, while the gameplay mechanics and content don’t improve in any way.
However, the experience of the added ray tracing (although this is subjective and some may argue that the reception of a period game as it actually looked in its time has its merits) is visually quite pleasing. However, if you argue that today’s games lack more than just graphical eye-candy compared to the inventive qualities of classic titles, then actually the remixing of those classics is something that can put pressure on today’s production by making these old games, now in more attractive guise more accessible and better able to demonstrate the viability of their content itself.
After a brief taste of the original Tomb Raider in the original DOS engine with rudimentary 3D acceleration and textures and models appropriate to the wooden era of 3D gaming, I find the game somewhat unaccessible in this form – even as someone who actually lived through that era and did play those games back then. Accomodading to this look and being able to naturally navigate and move around in it is likely something that you lose over time. With RTX Remix’s rendition of the Open Lara RTX modification, you’re playing something visually different, but on the other hand, this way you have a better chance of appreciating that level design that was praised at the time (albeit at the cost of slightly distracting elements like having to add the flashlight tool to the game).
In this form, younger audiences are more likely to appreciate why Tomb Raider gained such a fame and cult following in its day, and are more likely to understand why did the original (and how iconic in its day!) design of the protagonist get such an impact, without is looking so absurd in comparison to the heroine in the modern reboots.
However, we don’t mean to condemn the original versions of the games. As mentioned, they belong to the history and present the one and only original character of the game. Just as preservationists have come to understand that it makes sense to protect and preserve old works of art and architecture instead of tearing them down or remaking them in the random currently popular style of the day, we must not “erase” the original, but accept remixed games as an alternative to it. However, compared to the insensitive and destructive way in which, say, the “enhanced” edition of Baldur’s Gate 1 was made, I find Portal with RTX’s handling quite good. But it’s also true that the technological level of the original Portal is good enough that the game doesn’t cry out for a facelift as desperately as the original Tomb Raider does.
It’s quite interesting how much ray tracing lighting can help, even if the original primitive models and textures are left in the game, as mentioned in the Tomb Raider visual review. While this doesn’t take advantage of all the possibilities of the RTX Remix technology, it actually does, at least on the surface, seem like an interesting approach to make a game remaster: preserving the assets makes it a very responsible and original-respecting way, while still making an archaic game more digestible, and this doesn’t require heavy invasive changes that risk destroying the soul and style of the game.
On performance in RTX Remix games: Even the GeForce RTX 4080 Super is not an overkill
Full ray tracing with RTX Remix is very demanding on performance. Don’t be fooled into thinking that since you deal with a game fifteen years or more old under the hood of a mod, it should run like a champ on modest GPUs. We tested performance with the second fastest GeForce RTX graphics card of the current generation (the RTX 4080 Super), which is inferior only to the GeForce RTX 4090 in performance, but we still found that you practically must rely upscaling.
In Portal RTX, you need a GeForce RTX 4080 Super to achieve 50 FPS at native 1920×1080 pixel resolution without frame generation (but minimum FPS will be lower). It’s only with DLSS Quality that you’ll get to exactly 60 FPS. Without ray tracing, you get hundreds of FPS in the original game, and you’re probably only limited by the CPU (performance is around 290 FPS regardless of resolution).
At higher resolutions you are basically doomed without DLSS, especially in 4K where native FPS in Portal with RTX are close to being in the single digits. To get 60 FPS in 4K, you already have to combine enabled frame generation with DLSS Balanced (as you’re already below 50 FPS with Quality). On the plus side, it’s good news that you don’t have to downgrade all the way to Ultra Performance – but that’s probably inevitable with lower end graphics cards models. And the lower or older the GeForce RTX you have, the lower the resolution and FPS it will be able to handle.
At 1440p resolution, the performance of the GeForce RTX 4080 Super is more promising, and with DLSS Quality including frame generation, the average (but not minimum) values are over 100 FPS. Without frame generation, you still can’t get to 60 FPS while staying at DLSS Quality (56.9 FPS on average), but it seems that with DLSS Balanced, 60 FPS could be achieved even without frame generation (we didn’t test this combination).
You’ll only get really high FPS at 1440p and 1080p resolutions when you simultaneously use frame generation which doubles the screen frame rate (but of course you have to remember that these are just interpolated frames, so it’s not exactly ideal to have 60 FPS after Frame Generation, since that means the game is realistically rendering 30).
Even for simpler mods, there is a full performance tax for full ray tracing
And it’s not just Portal with RTX, although it’s actually a bit more challenging than other games. Even the Max Payne and Tomb Raider mods end up having pretty similar requirements, where at 4K you basically need to play with DLSS Balanced plus frame rate generation enabled (but that only means you get basic 60 FPS, which isn’t ideal when it’s after frame rate generation) and for 1440p you still need to use at least DLSS Quality with frame rate generation.
In FullHD, however, you can almost play in native resolution (almost 60 fps) or with DLSS Quality (60 fps) without using frame generation. Frame generation added gives you almost double the FPS.
There are some differences in the performances of the three games. Tomb Raider is a bit faster than Max Payne and Portal with RTX is a bit more challenging than both of the fan-made mods. However, the differences aren’t that big, we’re not talking about a 2x difference for example. So it looks like for ray tracing via RTX Remix, resolution is going to be the main performance variable, while the complexity (or in Tomb Raider’s case, primitiveness) of the environment and scene objects won’t make much of a difference, since there’s still a similar heaps of rays per pixel to analyze. This is probably why even ancient games become slow – their textures and polygons don’t matter much in the end, the performance is completely dominated by ray-tracing calculations that are analysing rays, meaning what matters is how many rays are in the scene, which seems to depend mostly on resolution when using RTX Remix, not the hardware demands of the original game.
English translation and edit by Jozef Dudáš
The testing graphics card Aorus RTX 4080 Super Master 16G, but also other GeForce RTX 4000 Super graphics cards are available in stock at Alza.de. Thank you for the cooperation!
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