REX Simulations Sky Force 3D: The FSElite Review

Product Information
REX Simulations
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REX Simulations
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Self Purchase
FSElite's preferred Flight Sim vendor is SimMarket. (Why?)

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When REX revealed Sky Force 3D back in 2016, it was one of the most talked about products at the time. The trailer showcased just how far their technology had come and what they could inject into the sim. The video and detail that followed demonstrated that REX were ready to make the weather in the sim both look and feel realistic, with the promise of tornados, fully 3D clouds and a weather engine that would revolutionise the way we interacted with the sky. Fast forward to 2018 and REX has finally released this long anticipated product.

Installation and User Interface

REX Sky Force 3D contains 20GB worth of photo-based environmental textures, but the team has managed to compress it down into a 4.6GB download. For many, this is still a significant amount of bandwidth, but REX has integrated their fantastic download system to help you along the way. You input your serial number, your details and select how you want to download. The automatic system will download any extra data as and when it’s needed. It worked really well and 15 minutes later, everything was ready to go.

Two more serial and detail entry forms later, REX Sky Force 3D was up and running on my system. The clean looking and dark-styled dashboard prompted me to enter a few key details about my favourite airport, what settings I want to use and if I’d like to install some of the community themes. Moving around the user interface is pretty simple, with each icon representing its associated section. At the bottom of each page is a useful ‘help’ button, which when pushed will bring up an overlay to assist you with what each of the options are and what each section does. Fortunately, I didn’t need use this very often as most of the set-up was self-explanatory.

Cycling through each page and you’ll see you’re able to look at the 3D cloud models, the environment, an interactive map, PTA integration and more. All of this is accessible at any time using the left-side navigation bar.

The first section I wanted to find out more about was the 3D cloud system. After all, this is a key highlight of the product. I was presented with a range of options. Some of these were quite obvious, such as enhanced overcast cloud basesand tornado/funnel. However, some were less so. For example in the ‘Alto’ section, there were various 3D model options for these types of clouds. For those less knowledgeable on cloud types I feel some visual clues or guides would be helpful. On top of that, there was very little detail in the manual about this element. This struck me as odd considering the importance of this section. Furthermore, this section allows you to adjust whether you have real-time sync mode turned on. Once you’ve selected your options, you can install over 1,500 weather models into the sim. I don’t know how, but the process is extremely fast – which is the same when importing environmental textures as well.

Within the environment tab, you are able to refine the way your sim looks. Everything from 3D cloud types to the moon textures can be adjusted here. You’ll be able to select from 22 different 3D cloud textures, 20 cirro-type clouds, and over 100 different sky textures.

There’s a huge range on offer and it’s presented well in the user-interface. You can also choose whether you want your sky textures to be static or use the 10-day in-sim cycle. This will make the sim feel more dynamic and vary the look of the atmosphere each time you fly. It’s great to see options available, either way.

Once you’ve installed the environmental textures into the sim, you will notice how fast they load. It will also save to your PC so you can come back to the set again if you make any adjustments you regret later on. Furthermore, whether it’s your favourite YouTuber, best friend or a complete stranger, you can search the vast community section for a theme of your choice. Download and installing takes little time and before you know it you can be flying with the same settings as the aforementioned. Sharing is just as easy and the community will have a sneak peak at what selection you’ve uploaded before they download. If you’re ever unsure, you can filter out certain types of conditions or base you download simply on the user rating system.

With theme and conditions all set up and ready to go, you can now import your route map and check conditions on the way. This is where the REX Weather Engine comes into play. The functionality of the map I found to be of a poor quality. It’s very slow, takes ages to react to your movements and having to user a slider to adjust the level of zoom is tedious and frustrating. It would be much easier if I could adjust the zoom with the scroll wheel on my mouse. Furthermore, the maximum zoom out level isn’t nearly enough for what I would need it for. On the other hand, you are able to place a range of overlays to give you more insight into the weather you will experience along the way. Whilst the map may display weather in a 2D view for you, it doesn’t always translate exactly into the sim. When the map said I should be in precipitating areas, there was very few clouds or other weather systems in the sim. I’ll go into more detail about the weather engine below.

The final section I want to talk about with the user interface is the ‘weather’ section. Here you will be able to view weather conditions for your selected favourite airports and search for specific weather. These two modes are quite basic and provide enough detail to assist those who can and can’t read Metar and TAF reports. Searching for weather is also quite easy. What surprised me is that this is all you can do with weather. Competing products would allow you to experience historical weather, or even more basically, create your own weather system. This is unfortunate as I have been unable to test out the tornado functions or experience how Sky Force 3D will handle hurricanes. Not to my own fault, but if I were to wait until one of those events were happening, and I was able to get to my sim in time, then I would be able to see them in action. Considering other products have offered these functions for years, it’s the first major sign of an area REX Sky Force 3D is really lacking.

Although not tied to the user interface itself, it’s worth nothing that there’s an in-sim menu that will allow you to see surface weather, wind and temperature aloft and finally a weather briefing. The weather briefing is a robotic voice of the nearest airport to your position. I find this incredibly strange as even with a flight plan loaded, it doesn’t give me a brief on my departure or arrival airports, nor even allow me to have this option in the menu. I also encountered some weird bug where I had 4 instances of the menu selection appearing.

Textures on Offer

As previously mentioned, there are 20GB worth of textures on offer with REX Sky Force 3D. All of them come in a range of resolutions meaning those using older hardware and / or simulators can enjoy the product without fear. There’s also a neat tool within the user interface that informs you what the likelihood of getting an OOM will be with your current settings.

What I liked most about the textures was the variety on offer. Whether you were cycling through the cloud or sky textures, there’s something someone will enjoy. Even cooler is the fact many of the textures are named to regions. For example, there’s a sky set named “London” which has the atmospheric visual of London (polluted) air. There are loads of examples like this which make it easier for you to decide what best fits your type of flying. It would be cool if in the future the software can detect your route and dynamically inject these textures into the sim – giving you a truly immersive environment.

In general, the sky textures are stunning. They add a lot of immersion to the sim – especially if you use the 10-day cycle. I loved loading the sim each day to experience a different set. Dawn and dusk looked especially beautiful with the sky blending perfectly without visual oddities. I did note that when switching texture sets, it jumped to the next instead of dynamically changing nice and smooth. What I mean by this is that the textures between time of day didn’t cross-fade into one another – instead they just switched to the next set in the cycle. Maybe I’ve been spoiled by other products, but in this day and age, I would now expect it from all software that provided a similar experience.

It should be noted that unlike past REX products, Sky Force 3D focuses primarily on textures found above eye-level. This means don’t expect any runway or taxiway textures you may have seen before. This is purely for the sky (hence the name).

Obviously a big part of that is the cloud textures, and 3D models. One of the most important elements of the product is how REX have managed to increase the number of cloud variety the sim can contain and display. This is what gives those storm clouds the daunting effect they have. It also means the clouds won’t look like popcorn and continuously repeat throughout your flight. REX has made it clear that these big, fluffy clouds you see are rendered in 3D, and are not 2D sprites you may be familiar with. This has been done to ensure that flying through them depicts the feeling of flying through the water vapour.

For the most part, they look stunning. They have spectacular texturing applied to the models which gives this impression of giant masses of cloud sticking together. It’s an incredible sight, and enhances your experience. As you get closer, you start to see how they actually appear to be more 2D in manner. Tim was kind enough to record some footage of this which I’ve included below.

Skip to 1 minute 40 to see the more interesting elements

It’s interesting to note that the clouds don’t move in a 3D space and are pretty static. Furthermore, the angle of the clouds appears the same and doesn’t change with your movement. Again, this suggests that they’re not as 3D as first imagined. Furthermore, the colourisation of the clouds doesn’t appear natural in some instances and adds a bit of a cartoonish effect to them. With that in mind, there are moments of beauty. During daylight on a grey and cloudy approach into Frankfurt, the colouring was stunning and gave the impression of a dull and dreary day.

Flying through them feels great. REX has incorporated a neat effect that gives you the sensation of flying through them, rather than the appearance of someone dropping flour onto your windscreen. It makes flying through even the most dangerous of cells a visually pleasing experience.

As you break through clouds, you’ll soon notice the enhanced sun effect included with the package. Whilst many people will love how it makes their screenshots look, it’s also highly unrealistic. The amount of flare and effect you get isn’t what the human eye would see in real life (not suggesting you look directly at the sun, by the way). I enjoyed how it made the sim look, but this is where I think REX sometimes gets confused. They aim for realism, but sometimes get caught up in what makes the best screenshots. A fine line to cross, and this is very subjective.

Fog, dust, rain and mist have also been given a makeover, and you’re also able to adjust what sounds you hear from lightning and rain. Each element of the atmosphere is changeable and as previously mentioned, you can save your themes or download your favourites from the community channel.

Weather Engine

REX has marketed Sky Force 3D as a revolutionary product that would change the way we view weather in the sim. No more would thunderstorms simply be nice to look at, but that they would impact the aircraft in realistic ways. Not only that, but it would make the whole experience more smooth and realistic. No more pop-in clouds, no more sudden changes in weather and no more dramatic shifts in wind.

The weather engine picks up data from over 70,000 data points across the globe meaning you will have up to date weather at all times. It grabs a lot of data, but impacts your bandwidth very little. It’s quite impressive to see the data load into the sim so quick! With all this information, the weather engine will then complete lots of calculations to produce what it thinks would accurately represent the weather, cloud structures and so forth. From a visual standpoint, the weather engine did a great job at creating unique and interesting cloud fronts and formations. This is helped by the real-time structure process that takes place within the sim.

Whilst visually, it was highly impressive, I had a few issues getting it to function in the sim correctly, despite following the instructions. A few computer resets later and I managed to inject the weather correctly. The most common issue I found immediately was the mismatch of information. The sim would display a bright and sunny day, but the METAR was reading clouds and rain. It only occurred once or twice, but it was a little frustrating. Once I moved past the initial issues, I loaded up a few flights to experiment with how the engine would handle different scenarios.

My first test was to see how it handled weather in the same location over a period of time. I loaded up the sim, took off and the skies were bright and a few clouds were scattered around. I was pleased with the visual representation and the cloud textures looked beautiful on the well-done sky textures. After a couple of hours, I began descending back to the runway when the info bar popped up to say synchronisation has been completed. With that, those white fluffy clouds disappeared and I was 1000ft deep in thick, stormy clouds. There was definitely a weather front coming into where I was flying, but the complete shift in weather was awful. My aircraft lost control, the winds battered me about and suddenly that immersion was completely lost.

Next flight – a short haul in Europe. Flight loaded, skies sunny with few clouds. A beautiful flying day. As soon as I take off, the synchronisation bar appears and all those fluffy things vanished. No fading, no changing of direction, but completely vanished. I checked the METAR and it still said there were clouds about, so why REX Sky Force 3D decided I no longer needed them was beyond me.

And this theme continued throughout my testing. Each time the synchronisation took place, the weather would change – and most of the time in quite dramatic fashion. This is incredibly disappointing to see after all the advances we have seen in simulator weather engines. It’s frustrating as you’ll be flying through some of the most realistic weather fronts you’ve seen in a sim, but for it to change, make an impact on your aircraft and impair your vision ruins the immersion

Wind aloft information, turbulence and haze worked fine, although there was some shifts here and there. Nothing noticeable, but not a smooth transition. The same goes for visibility – there doesn’t appear to be much in the way of transformation. It’s a shame, because the visualisation of it all looks great. If you want to, you can adjust the strength and other settings in the user interface I’ve mentioned above.

Clouds will pop in, haze will just clear and rain will turn to shine at the snap of a finger. This isn’t “total atmospheric immersion” as the tag-line claims it to be.

As I continued to experiment with different options, I decided to try turning it off. Fortunately, even with the weather engine off, you’re able to enjoy the textures in the sim. I’m not really clear what you lose from the atmospheric effects by having the weather engine off. Storm clouds were still present, cloud layers still performed well, and the visual quality of the sky remained the same. I imagine more complex things like tornados may not be produced with their weather engine off.

The fact that REX make it so clear and give users the option to disable their weather engine and allow competing engines to work with their product is both good and bad. Good in that they’re open minded, as people will have their preferences, but ultimately, the weather engine makes up a big portion of what this product is. As such, I feel REX missed out completely on delivering a good weather engine. As such, I often used the combination of HiFi’s Active Sky for P3DV4 with REX’s texture set from Sky Force – a combination that I shouldn’t have had to use in the first place if REX had done the job right from the start.

How it Compares

It should come as no surprise that for me to get a clear picture, I needed to compare Active Sky for P3DV4 against REX Sky Force 3D. Both were announced at the same time and are the latest engines from both developers.

For the comparisons, I tested a few conditions, saved the flight and loaded them up with each engine running. I then tried running the same scenario with REX Sky Force 3D supplying the textures and Active Sky for P3DV4 as the weather engine. Note: I did my best to capture them all from the same angle, but it proved difficult in some scenarios.

Cloud Formation


Rain Clouds

Storm Clouds

Overcast Clouds

Tenerife South and how the engine handles clouds peaking through mountains

Heathrow on the ground with drizzly clouds

As you can see, there’s considerable difference. REX definitely provides the most visual appealing experience and actually performs better in most cases than Active Sky. However, as you can see, it’s the right image that provides the best of both worlds. You get an incredible weather engine, plus the beauty of the high-resolution textures from REX.

It’s not just the visuals that make a difference. If you solely use REX’s platform, then you’ll also lose integration with PMDG products in the weather radar. For someone who has invested heavily in those planes, it’s a shame to lose an excellent feature.

On the other hand, there are some incredibly neat features in REX’s offering that can’t be found in competing products. Perhaps the most advanced feature is the ability to sync your weather with those you’re doing a shared cockpit flight with. When I tried this, it worked really well. You would both be in the same ‘cloud’ and experiencing the same winds and weather. You could literally look out the window and say “hey, look at that storm cell” and your co-pilot could look and say “oh yeah, let’s avoid that”. It’s a level of immersion I’ve yet to experience from any other weather engine on the market.

Value for Money?

With my disappointment in the lack of options in the user interface, I feel the value of the product comes mostly from the textures and 3D cloud models on offer. As I’ve said, and shown you, they are stunning. The cloud systems add a great deal of variety to the sim and I feel the sky textures offer a great deal of realism to the sim (even if they do change without any kind of fadeout). However, with a broken weather engine, I have a hard time really justifying the price tag. More so when you consider the fact that REX have made multiple statements suggesting that their upcoming Weather Force product will be required to truly fix all of the issues with Sky Force. It’s a confusing and costly proposal for the community.

Then there’s also the possibility that you already own a previous REX texture pack and are happy with your current weather engine. Whilst these textures and models are much more advance than anything they’ve produced before, some may find it hard to justify the price tag for something that will give a somewhat similar experience.

Ultimately, what this comes down to: does the package do everything it sets out to do? This is where the value mark really matters and from my experience it falls short. There are certainly some moments of excellence with the product, but when a key feature of the system lets you down, that doesn’t scream value for money to me.


Overall, we felt...

Presentation 6
Features 4
Value 4
Performance 8

Overall, we felt...

5.5 Out of 10 How do we score? | Feedback? REX’s Sky Force 3D is a product of 2 halves. On one hand, you have an excellent texture replacement system for weather, clouds and sky-sets and on the other, you have a poor, buggy and frustrating weather engine. Whilst the visuals are impressive, the functionality and instability of the product means I struggle to fully recommend the product. For me, REX Sky Force 3D is style over substance, which is majorly disappointing considering the hype and marketing build up over the past few years.

Tags : REXSky Force 3DUtility
Calum Martin

The author Calum Martin

I have been an avid fan of Flight Sim since the release of ‘2000 and have developed my love for aviation ever since. I have the knowledge and experience to really deliver an excellent aviation community. Although no real life flying experience, I have a good understanding and always learning more and more.