Portal With RTX: A Reflection on A More Reflective Portal Experience

“Just because something doesn’t do what you planned it to do, doesn’t mean it’s useless.” –Thomas Edison

Back in September, NVIDIA’s announcement of Portal With RTX generated a bit of buzz: the original Portal is now fifteen years old. To showcase their new line of Lovelace GPUs and RTX Remix, NVIDIA also determined that Portal was worth reimagining. Using machine learning, RTX Remix dynamically computes how lighting should behave, allowing it to interact with objects in a 3D space in real-time. RTX Remix uses path-tracing, which uses a comparatively simple algorithm to render high-quality images at the expense of performance; as lighting becomes more sophisticated, path-tracing becomes more demanding, and typically, games utilise more efficient variants of path-tracing that may not be quite as visually impressive. Here in Portal With RTX, NVIDIA Remix’s use of path-tracing means that the end-result is a highly advanced showcase of what lighting effects are possible: because everything is done using ray-tracing, illuminations, shadows, reflections and even refractive effects are especially impressive, breathing new life into an iconic game. There is, however, a trade-off: because of how computationally expensive path-tracing is, Portal With RTX demands the most powerful hardware in order to run at maximum quality and resolution. In order to play Portal With RTX at 4K and 60 FPS, with everything set to ultra, NVIDIA’s RTX 4080 is recommended. On the other hand, while the minimum GPU suggested is the RTX 3060, folks have reported that they’re struggling to run Portal With RTX, even though they’re running video cards that are more powerful than the RTX 3060. The variability in performance and experience demonstrate that, as exciting as ray-tracing techniques are, and as exciting as the prospect of having real-time ray-tracing hardware become mainstream is, the technology still has a way to go before it can become widespread. For the present, real-time ray-tracing remains more of a curiosity, but when judiciously applied, the lighting and visuals can act as a fantastic showcase for what is possible.

The extreme requirements in Portal With RTX has meant that getting the game to run has been a toss-of-the-coin. On my RTX 3060 Ti, which is about 30 percent more powerful than the RTX 3060, I’ve managed to get Portal With RTX running at manageable frame rates, with reasonable quality. Although the RTX 3060 Ti is far outstripped by the RTX 4090, the fact that this mid-range card is able to run Portal With RTX without any major issues speaks volumes to the build I put together back in March. In this way, I was able to revisit an old experience given a fresh coat of paint. Initial impressions of Portal With RTX had been met with skepticism: video games journalist Ben Sledge writes that the highly reflective, clean surfaces of the remaster defeats the visual impact of the original game, where there had previously been dull, lifeless walls, and as a result, the soul of Portal had been “ripped out”. As a result, the remaster was unnecessary, and hardly any justification for playing Portal With RTX. In practise, this is untrue; although Portal With RTX has new, high-resolution textures to showcase just how sophisticated the RTX Remix lighting is, the overall aesthetic in Portal With RTX remains respectful to the visuals of the original. NVIDIA had chosen to showcase segments of the game where the differences were especially profound, but for folks playing through Portal With RTX, the visuals actually aren’t too dramatically changed: after marvelling at the reflections from the Heavy Duty Super-Colliding Super Button, emissive effects from the high-energy pellets and dynamic shadows (all computed in real time), it’s time to focus on the puzzles themselves. Moving through the test chambers, it is apparent that, rather than depriving Portal of its character, the updated visuals actually speak to an Aperture Science that is at its prime. Clean, polished surfaces show an institute that was, at one point, a serious competitor to Black Mesa. The new visuals in Portal With RTX serve to both bring life to an old classics, as well as tell a different story about Aperture Sciences, and in this way, one can make a clear case that Portal With RTX is anything but soulless. Of course, if one wished to experience the original, that option continues to remain viable: the old game isn’t going anywhere, and upon returning to it after completing Portal With RTX, it is apparent that the original still holds up extremely well.

Screenshots and Commentary

• For me, Portal With RTX represents a test of my hardware’s capabilities. I’d already played through and wrote about Portal previously, having greatly enjoyed the game’s innovative mechanics and sense of humour. On this particular play-through, I completed the entire game in the space of an hour and a half, having already gone through the game and therefore, had a full knowledge of all of the nuances to how each puzzle was to be solved. Instead, a part of this experience was to see just how detailed everything looked now that real-time ray-tracing was implemented.

• To put things simply, Portal With RTX looks amazing. This is most noticeable in the Heavy Duty Super-Colliding Super Buttons on the floor. Whereas they’d been made of a dull metal previously, they’re now reimagined as glass or ceramic buttons and reflect their environments in detail. To show that off, I’ve stacked a pair of Weighted Storage Cubes here, and positioned myself so I could see the wall lights and portal reflected on the buttons’ surfaces. Ray-tracing effects have previously been implemented in first person shooters like Metro: Exodus and DOOM: Eternal, but with how high-paced they are, there’s little time to appreciate the visuals.

• On the other hand, Portal is the perfect place to showcase what ray-tracing can do. The high energy pellets, for instance, now emit their own light and act as a mobile point light. While this is nothing impressive, the fact that everything in this scene is ray-traced shows what’s possible with the technique. One detail I did particularly like was the fact that the toxic liquid in Portal With RTX, a dull, greenish-brown sludge in the original, is now more reflective, and thanks to ray-tracing, any changes in the environment are now visible on the liquid’s surface, too.

• For me, I have DLSS on and set to “Quality”. I’m using a custom graphic preset with everything turned up, except the maximum number of light bounces is set to four. With these settings, the game runs at around 45 FPS, and I didn’t experience any crashes during my time in Portal With RTX. Although quite a ways lower than the baseline of 60 FPS for smoothness on my monitors, the game remained very playable, and I was able to complete it without any difficulties from a hardware standpoint. With this being said, it is clear that for me, Portal With RTX was not being rendered at native resolution, and instead, was likely being upscaled using DLSS.

• DLSS (Deep Learning Super Sampling) refers to NVIDIA’s upscaling and inference technology which renders images at lower resolutions and then upscales the images so performance is increased. This translates to better frame rates for players, allowing lower-end GPUs to still keep up. The technology was introduced with the Turing Series, and with Lovelace, DLSS 3 was brought in: DLSS 3 is exclusive to the Lovelace series, but even the older DLSS 2 (which is available on the Ampere GPUs) offers performance gains. For most of the games I play, I have more than enough hardware to render everything at native resolution.

• In the case of Portal With RTX, the image quality is a little less crisp than if everything were rendered natively. With DLSS off, I average around 15-20 FPS, so in order to have a playable frame rate, even at 1080p, I needed DLSS to be enabled, although even at the “quality” mode, I was able to maintain about 40-45 FPS. I estimate that folks running an RTX 2080 Super or RTX 2080 Ti should also be able to play Portal With RTX without too much problem after adjusting some of the settings, but anything below an RTX 3060 is unlikely to be able to run the game.

• The requirements for Portal With RTX are surprisingly steep because RTX Remix is, simply put, expecting the Lovelace series of GPUs to brute force things. When optimised, real-time ray-tracing can be quite performant, but here, Portal With RTX is meant as more of a demonstration of the technology. As such, as incredible as Portal With RTX looks, it’s also one of those games that can’t be recommended to Portal fans unless they already have the hardware or are intending to upgrade their hardware and utilising it fully: it should go without saying that spending 2200 CAD for an RTX 4090, or 1650 CAD for an RTX 4080 (neither of which are in stock at my local computer store) just so one can play Portal is not a good use of money.

• Having said this, if one has a legitimate use case for a Lovelace GPU, then Portal With RTX becomes a novel experience. Here, I will share a laugh with readers at the expense of Tango-Victor-Tango’s John “Fighteer” Aldrich, who had posted to the forums shortly after Portal With RTX‘s announcement, wondering if his GTX 1060 would be able to run the game and concluded he should be okay since the GTX 1060 was capable of ray-tracing. Although the 6 GB model of the GTX 1060 can enable DXR and do some ray tracing, performance leaves much to be desired – if memory serves, in games with basic ray tracing, the GTX 1060 drops to around 15 FPS with DXR enabled. Seeing Fighteer’s misplaced optimism that the GTX 1060 (while a fantastic card) could run Portal With RTX is laughable and typifies the behaviour of Tango-Victor-Tango’s userbase’s tendency to not completely research their topics before speaking out.

• Shortly after Portal With RTX released, Fighteer found himself eating crow and commented on how he now had an incentive to upgrade in the future, and I return to my previous statement – if one is planning an upgrade to an RTX 4080 or 4090 purely so they can play Portal With RTX, it is likely an unwise expenditure. For content creators who stream Triple-A titles, a top-tier GPU like the 4090 makes sense, and similarly, someone doing AI research will find the 4090 a suitable investment. However, for a vast majority of gamers, the RTX 4090, and even the 4080, is overkill. Having a video card like these for 1440p gaming as a hobby is akin to having a supercar, and then only using it as one’s commuter vehicle.

• Because of the financial aspect, I do not expect Fighteer to spring on an RTX 4080 or 4090: in fact, I comment that it’d be more prudent now to wait for the mid-end Lovelace cards before making a decision. For me, I’ve settled into a pattern now: after I buy a GPU, I try to make it last at least three generations before upgrading again, and whether I upgrade depends on whether or not my current GPU can still run the games I am interested in on high settings while maintaining 60 FPS at 1080p. If my GPU cannot do this, then I will look at seeing whether or not the current mid-range GPUs can keep up with the upper-range GPUs of the previous generation.

• For instance, when I upgraded to the GTX 1060 from the GTX 660, one of the selling points about the 1060 was the fact that it offered near-980 levels of performance for a much lower price and a lower power draw. One of the reasons why the RTX 3060 Ti was so enticing, then, was the fact that it actually edged out the RTX 2080 SC. In fact, the 3060 Ti is ten to fifteen percent weaker than the older 2080 Ti, but at the same time, costs significantly less and has a lower power draw. For me, I don’t need the additional power the 2080 Ti offers because I’m still playing at 1080p, so the lower cost made the 3060 Ti the obvious choice.

• Since I made the call to grab a 3060 Ti, this left me in a position to try Portal With RTX out, and this is why I’ve been lucky enough to give things a go and see for myself what the technology could do. However, Portal With RTX is not a game worth upgrading a GPU for in this moment, but down the line, when more Lovelace GPUs (or the new generation) become available, more people will be able to give Portal With RTX a try. Surprisingly, most of Tango-Victor-Tango’s forums have been remarkable quiet about Portal With RTX, and most of the complaints about the game’s steep requirements are found at Reddit.

• My response to Portal With RTX and its requirements are that, I’m glad my desktop was able to handle it reasonably well (40-45 FPS at 1080p with things cranked up to ultra is nothing to sneeze at, considering that the recommended GPU is an RTX 3080), and moreover, even if the humble 3060 Ti could not run the game as well as it did, it’s not as though the release of Portal With RTX would take away from the fact that Portal still runs extremely well and is the original experience. As such, it makes little sense to gripe about Portal With RTX‘s changed aesthetics and steep requirements because there’s nothing stopping players from grabbing the original and having a good time with it.

• As I made further progress into Portal With RTX, I began recalling old memories of playing through the game for the first time. The puzzles came back to me relatively quickly, and I don’t mind admitting that I only had a minor bit of trouble with Test Chamber 15, but even then, after giving things some thought, all of the puzzles proved quite straightforward to complete. This was what allowed me to go through the whole of Portal With RTX with relative ease. On my original run of Portal a decade earlier, I had taken a total of three hours to complete the game since everything was new to me, but for my troubles, had a wonderful experience.

• I ended up replaying the whole of Portal two years earlier, during the height of the global health crisis. Replaying Portal brought back memories of a simpler time, and here, I pick up the iconic Companion Cube, which became an instant favourite with players. Its first utility is to act as a shield of sorts, protecting players from the high-energy pellets while they travel down the hallways. Here, the ray-tracing has a chance to really shine: the high energy pellets emit light and glow brightly, causing a unique visual effect in the metal-lined corridor that was simply absent in the original.

• The Companion Cube creates an interesting problem-solving scenario, since players must use their single resource in order to complete the objective, and for Portal With RTX, the updated visuals are especially impressive in Test Chamber 17 because there’s an opportunity to again showcase the lighting. Here, light from the Heavy Duty Super-Colliding Super Buttons illuminates the Companion Cube, and reflections of this lighting can be seen on the wall to the right. The slower pace of Portal is naturally conducive towards admiring the lighting effects.

• It suddenly hits me that we’re now hurtling through December at a breakneck pace: it only seems like yesterday that the month has started, but we’re now less than two weeks to Christmas itself. Yesterday evening, I was able to enjoy the first Christmas gathering with extended family in three years, and it was a pleasant evening of conversation and excellent food (prime rib with au jus, roasted prawns, skewered pork, mahi-mahi, carrots and Brussels sprouts with bacon and potato gratin). I’ve got another Christmas party lined up on Thursday with the office, but beyond this, I am looking forwards to a quieter Christmas Day with immediate family.

• 2022’s been an eventful year, especially with the big move and building of a new desktop back in March, but things settled down reasonably quickly, so I am able to look forward to some well-earned downtime at the end of the year. I am glad that I was able to get my desktop set up when I did: the ongoing microprocessor shortage has meant that new parts will continue to be hard to come by, and Intel forecasts that said shortage could last into 2024 because of a lack of manufacturing equipment. As a result, prices are unlikely to see any drops, and this has been most visible with the Lovelace series GPUs, whose flagship model costs more than an entire PC.

• The extreme price of hardware is what led my alma mater to remove their gaming PCs from the main library. When the new library had opened a decade earlier, the gaming computers were something students marvelled at and featured hardware comparable to my previous desktop. They received upgrades back in 2016, but when campus was undergoing a reconstruction project in 2019, the machines were decommissioned: some students have noted that their hardware was increasingly outdated, and beginning to fail, so the university decided to shelve these machines.

• As of 2022, campus has not purchased new machines to replace the old ones, and for good reason: picking up eight brand-new custom-built PCs wouldn’t be a good use of the university’s funding, especially when considering that a high-end laptop now can have comparable performance. On the topic of higher-end laptops, my best friend recently picked up a new laptop to replace an aging machine that’d been giving him no shortage of trouble. This laptop, the MSI Katana, is armed with an i7 12700H and an RTX 3070 Ti, which puts his machine as having 90 percent the performance of my desktop.

• With this, I am looking forwards to playing Modern Warfare II spec ops with him in the near future, and in the meantime, the both of us can gloat about being able to enjoy games while Fighteer is stuck moderating pointless debates at Tango-Victor-Tango because aging hardware precludes his spending time doing more enjoyable and productive things, such as checking out the real-time reflections in Portal With RTX. Admittedly, the visuals here are such that it would be easier to show the effects in a video, rather than through screenshots, but one hopes that the stills I’ve got still convey the advances in lighting effects.

• Back in Portal With RTX, after solving this puzzle, GLaDOS promises that there’d be cake, but for longtime players, what awaits is a hilarious outcome that also sends Portal into its second act. By this point in time, the sum of all of one’s experiences means that players should be able to quickly identify where portals should be placed in order to solve a given puzzle. In Portal 2, test chambers actually limited the amount of surfaces a portal could be placed on, which in turn would give not-so-subtle clues as to how things could be beaten.

• However, in Portal, even though test chambers are largely portal-friendly, the game still gives some clues as to where portals can be placed. High-energy pellets, for instance, will leave scorch marks on surfaces they interact with, and the receptacles for these pellets similarly illuminate a path so one has an idea of where to aim things. Portal is one of those games where the puzzles, while sometimes challenging, aren’t impossible: it feels rewarding to work something out, but it won’t take one an entire afternoon to figure out one test chamber.

• Portal is broken cleanly into two acts: the first is the test chambers, and the second is everything after players escape and do what they can to survive. From here on out, the game requires that players keep an eye on their environment and make full use of their creativity and ingenuity to survive. Along the way, scribbles on the walls will serve to guide one to their final destination, a one-on-one confrontation with GLaDOS. I found that Portal With RTX‘s second half was not quite as visually impressive as the first, but even here, the lighting effects are impressive, with things like the catwalks being rendered with reflections to give them a greasy, slippery sense.

• Pressing through the bowels of Aperture Science with ray-tracing, it becomes clear that while Portal With RTX had refreshed the original test chambers, the back corridors of Aperture remain mostly untouched, and this creates an even stronger juxtaposition between the game’s first and second acts. In these corridors and maintenance ways, the effects from real-time ray-tracing are still noticeable (fans cast shadows in real time, and metallic surfaces interact realistically with light), but for me, the most impressive addition is volumetric lighting, which gives the entire space a musty, dusty character.

• Owing to the volumetric lighting, spaces that were formerly dark are now much brighter than they’d previously been, and this brought to mind the changes that were made to Halo: Anniversary, where iconic spots on Installation 04 were rendered as being more detailed and bright than in the original. Fans were displeased with the changes, since the darkness had added to the aesthetics and unease those levels conveyed. By the time of Halo 2: Anniversary, 343 Industries took a much more respectful approach to things, and the game ends up being faithful to the original’s tone while at the same time, sporting much more detail.

• Portal With RTX is more similar to Halo 2: Anniversary, or perhaps Half-Life 2: Update, which touched up the visuals without dramatically altering the game’s style. This speaks volumes to how things like RTX Remix can be used to add new life to classic games, and while I would very much prefer a proper remaster, the fact that the technology exist means that, at least in theory, it’d be possible to run something like Half-Life 2 though RTX Remix and get real-time ray-tracing working. Of course, in a first person shooter, where frame rates do matter, I’m not confident the technology would produce the best experience, even if it does showcase how the potential for giving games new lighting exists.

• The sky bridge leading into GLaDOS’ chamber in Portal With RTX looks much as it did in Portal, although better lighting means more details are visible. Here, I will note that in the time since I’ve graduated, many parts of my alma mater have undergone dramatic renovations and changes, so some of the features that were present when I were a student are now gone, and the professional building is among the places that have changed. The office perched beside an atrium is gone, but this is actually one of the smaller changes; because it’s been six years since I was a student, the library tower and student services buildings have been completely replaced, and even the iconic “Prairie Chicken” statue was removed for a few years while construction was going on.

• Although lower frame rates are technically okay (anything north of 30 FPS is playable in the test chambers and while escaping), 45 FPS is more than enough to beat GLaDOS, and I had no trouble completing the final fight. Having said this, it is here, during the final fight, that frame rates do matter: beating GLaDOS, even though it is a relatively relaxed task, still demands some degree of precision and coordination, and a janky experience can prevent one from timing their jumps well enough to grab some of GLaDOS’ personality cores.

• Ninety minutes later, I had completed the whole of Portal With RTX and was treated to the final cut scene, wherein the infamous black forest cake is rendered using real-time ray-tracing. I found myself vaguely filled with a desire to enjoy some cake, and while the local grocery store sells black forest cakes for 16 CAD, the fact that we’re so close to the holidays means that other Christmas classics will soon dominate the menu (including my personal festive favourite, the chocolate Yule Log).

While ray-tracing has only really taken off with NVIDIA’s Turing series of GPUs, the techniques have been proposed since 1986 by James Kajiya, and during my second year as an undergraduate student, I put together my own ray-tracing method for dynamically computing fluid flow in complex paths for physics objects. The object of this project had been to see if I could solve the problem of the in-house game engine being constrained to linear models of fluid flow. As the lab was trying to simulate more complex paths, the only solution was to approximate these paths by placing what we called “flow fields” into vessels. This was a painstaking task, and the concept of ray-tracing had been a promising way to simplify things. I was asked to explore an algorithm that each physical agent in the model could use to computer its path, and over the course of a summer, fine-tuned it so that it could convincingly “nudge” objects flowing to follow a path for visualisation. While the method had similarly been computationally demanding, it demonstrated that it was possible to push physical agents through any arbitrarily-shaped vessels without manually defining the paths. At the time, hardware meant that doing this for a few hundred objects and maintaining 30 frames per second was an accomplishment, but as more agents were added, performance correspondingly took a hit. Through this summer project, I felt that ray-tracing was a fantastic way of simplifying some tasks at the expense of performance, and while hardware today has improved, the trade off between convenience for the developers, and an end user’s experience, is one that real-time ray-tracing continues to face. In the case of Portal With RTX, using an AI to remaster lighting in a game is an exciting new development, and while it may not produce an optimised product for retail, evolving technology and hardware means that such methods simply open up more possibilities: rather than remain disappointed about how Portal With RTX cannot run on all hardware, one can instead look to the technology as simply another sign that things will never stagnate and continue to advance in new directions: although at present, path-tracing as RTX Remix implements it remains something that needs to be brute-forced, over time, improving software techniques will make things more efficient, and players will be glad that the technology had a starting point from somewhere iconic and reasonable.