A couple of months ago, we had the pleasure of interviewing Cloud Imperium’s Engine Technical Director, Sean Tracy, who shared with us some interesting new information about their upcoming PC exclusive space sim, Star Citizen. We talked with Sean about a lot of topics such as the game’s PC-only nature, mod support, DX12, some of the key graphical features of Star Citizen, as well as the game’s PC requirements and its multi-core CPU support. Enjoy the interview after the jump and big shoutouts to Cloud Imperium’s David Swofford as without him, this interview wouldn’t be possible!
DSOGaming: Before we begin, please introduce yourselves to our readers.
Sean Tracy: My name is Sean Tracy and I am the Engine Technical Director at Cloud Imperium Games working on Chris Robert’s Star Citizen.
DSOGaming: Star Citizen is a PC exclusive? What can PC gamers expect from this PC game in terms of visuals, features and PC options?
Sean Tracy: Gamers can expect their PC’s to be pushed to the max as we are not bound ,as developers, making a game for the “lowest common denominator” which classically for most companies are the consoles or even mobile hardware. Without us having to effectively optimize to the point of being able to run on the limited hardware that is present in the consoles we are free to push the boundaries of what is possible in real time on current and even next-generation PCs. The PCs will always be beyond what console hardware has and further we are dedicated to giving enthusiasts that want to test their machine’s mettle with the options to be able to do that. This is truly a game for PC gamers who want a game built from the ground up for the PC and not up-rezzed or ported over.
DSOGaming: Xbox One and PS4 have just been released. Are they powerful enough to handle Star Citizen and do you plan bringing the game to them after the PC release?
Sean Tracy: There are currently no plans to bring the game to consoles. With that said, we don’t ever want to say “never.” There’s always a possibility for a console launch down the road, but since most of our development is PC specific, it would be difficult to make Star Citizen for a console in the near term.
DSOGaming: Star Citizen is powered by CRYENGINE? Why did you choose Crytek’s engine over Unreal Engine 4 or other engines?
Sean Tracy: I happened to be part of the group at Crytek that demonstrated CryENGINE to Chris for the first time. It was 2010 and I met Chris for the first time whilst my job at Crytek was Engine Licensing. I knew even then that this title would be a huge success and thus pursued Chris doggedly. I knew that this game would fit the CryENGINE quite well and that the technology would be the best launching point for all the improvements and requirements that Chris was looking for. Eventually it took a few of us on the Crytek staff working internally after hours with some key members of Chris staff to help create that original crowd funding video. I think that video closed the deal for Chris as he could see his vision realized. So short answer I like to think it was due to the small group of huge Wing Commander fans internally at Crytek willing to help and put some time in on the prototype.
DSOGaming: Tech wise, what are the key tech features of Star Citizen, and what is the one feature that you are really proud of?
Sean Tracy: This is a fantastic question. At present there are so many key features that I’d be hard pressed to start listing them. Since we are developing the game in modules each module has its own set of unique features and needs. One of the biggest ones that all the modules are benefitting from is that we’ve modified the z-buffer in the CryENGINE renderer and upgraded it to a 32 bit inverted depth buffer vs. the 16 bit linear version that is shipped “out of the box.” This might not sound like a drastic thing, but we are now able to render massive objects 1000s of KM with great accuracy. Yet it still allows us to come into first person and retain cm level precision in the renderer. This un-binds us from some fairly typical limitations including map sizes and more.
One of the key features being engineered as I write this is that for us to support true solar system scale we must switch many of the internal systems of the cryengine to x64 bit double precision. This would be for things such as objects placed in the world, physics calculations over long distances whilst maintaining high accuracy and pretty much anything that requires some kind of world position. It’s a very interesting topic and I think Star Citizen is unique in the sense that we are likely to be the first ones ever to do this to such a degree and with such fidelity.
One last feature I wanted to mention is probably the most exciting and again another novel one for Star Citizen which is the concept of a local physics grid or basically a relative physics world within another larger one. This is how we are able to keep the physics in place and gameplay capable even whilst walking around ships that might be flying at hundreds or thousands of meters per second. This also gives a super unique sensation and gameplay as you are properly inside your ship and your physics is relative to that instead of the larger world. This was first demonstrated at Gamescon of this year and again at CitizenCon and we are very excited to share more of it very soon.
DSOGaming: These past few years, most games were taking advantage of only three CPU cores. However, Crysis 3 was one of the few games that benefits from quad-cores and hexa-cores. Will Star Citizen take advantage of more than four or five CPU cores, and will there be performance differences between quad-cores and hexa-cores?
Sean Tracy: Star Citizen is massively parallelized and actually the CryENGINE makes it relatively straight forward for us to manage the threading of many of our systems. As you pointed out CryENGINE has been moving in the direction of multi-core CPUs for quite some time and thus there are job managers and macros in place to make it a bit easier to thread your own functions. So to answer the question directly…absolutely, Star Citizen will take advantage of as many cores as it can.
In terms of the impact on performance, that is hard to say until we are closer to the end! I can say though that we aren’t necessarily CPU bound in this project, and even generally the CryENGINE. It’s quite common for the CPU to be waiting on the GPU so extra cores won’t necessarily make that waiting any faster. With all that said, when playing over the network and even possibly in the persistant universe expect a bit higher load on your CPU but I would be surprised if we ever became more CPU than GPU bound.
DSOGaming: What’s your opinion on OpenGL and Direct 3D? OpenGL is said to support a lot of low-level access commands. On the other hand, MS introduced DX12 (an API that offers – like Mantle – lower-level access) at this year’s GDC. Will Star Citizen support DX12?
Sean Tracy: My opinion on Open GL and Direct 3d is that they both have their idiosyncrasies. We are happy to let CryTek, however, manage a good deal of the overall API Support for the engine. For example, Crytek has worked on a Linux Open GL version of the engine which is quite comparable to the Direct 3d version. Regarding DX12, I can’t yet answer fully. Of course since we expect to develop for PC this will be something quite important. There are many exciting features too with DX12 and because it gives some of the same benefits that Mantle provides it’ll be hard to say no. Two of the big features from DX12 that I’m personally interested in is batched render targets (as the CryENGINE has 100-150 render targets at any one time), as well as OIT (Ordered Indepdant Transparency) for things such as glass, alpha blended particles and more.
DSOGaming: We’ve heard that you got a PS4 devkit recently. Have you experimented with it and what’s your opinion about it?
Sean Tracy: Never! 🙂 I can speak a bit to the PS4 though as I’ve just come away from working with it at Crytek. My opinion on it is that it’s much better to develop for than PS3 ever was. It’s powerful and Sony has put the right tools in place for developers…tools that aren’t nearly as obscure or unintuitive as they may have been in the past.
DSOGaming: What’s your opinion about PC gaming in general? Is it a profitable platform? Do you think that mods are essential for PC games or are they simply endanger all DLC plans that most publishers are planning prior to the release of their games?
Sean Tracy: Absolutely PC can be a profitable platform. I think CIG’s world record of 60+ million demonstrates that!
Now for the topic of mods. This is a topic that’s very close to my heart as modding is what gave me and many of the best people I’ve worked and continue to work with their jobs in the industry.
I once heard someone say something to that effect that if you have to wait for someone to pay you to do something, you don’t really want to do it! I personally think mods are essential. The undercutting of DLC is really a console and even a classic retail release issue that won’t be present in Star Citizen. We hope to have many kinds of modding available to certain modules of the game (as obviously it’d be hard to mod an MMO!).
DSOGaming: Star Citizen is perhaps the only game that supports PhysX and Mantle. Will it support GPU-accelerated PhysX effects and if so, what kind of effects should we expect? Will you be also using the latest PhysX 3.0 SDK?
Sean Tracy: At this time, Star Citizen doesn’t build the PhysX SDK into it. We do rely quite heavily on Crytek for features such as this to be integrated into the CryENGINE, making the features supportable from Crytek. With that said, if there are tools and features that we need that will not be integrated into the CryENGINE we happily create these ourselves. It’s important for us to keep this partnership close as it gives us the benefit of having two companies working con-currently on integrating new technology such as Mantle and PhysX.
DSOGaming: Star Citizen’s Arena Commander Module requires at least 8GB of RAM with a DX11 GPU. Can we expect the final product to run on systems with less RAM and will it support DX10 GPUs?
Sean Tracy: Likely not. We are creating this game with the PC gamer in mind. Of course performance will be optimized much further than our current version of Arena Commander but I wouldn’t expect that we would drop the system requirements any time soon. Additionally on the Direct X 10 front, as almost every engine/rendering we’d like to put in relies heavily on DX11 and even DX12 or Mantle I can’t see DX10 cards even existing much longer. It’s difficult to say, but I don’t expect that the majority of gamers would even have DX10 cards anymore and so for us to continue support it wouldn’t make sense.
DSOGaming: Have you experimented with adaptive tessellation in order to eliminate the pop-in issue (for both spacecrafts and planets) that plagues all games? Or will you be using different LOD levels (like the majority of games)?
Sean Tracy: We fully use adaptive tessellation across any asset that uses tessellation. The CryENGINE has an extremely sophisticated tessellation scheme and we fully use it to our advantage.
DSOGaming What are the challenges of creating such a huge space combat game?
Sean Tracy: There are many challenges, but first and foremost is the sheer scale that we are dealing with. We are doing entire solar systems that are completely seamless. Prior to this, most levels that had even been created in CryENGINE were only a few kms (4-8). But when we are having to represent millions and billions of kms there are major changes, namely a conversion of the engine to use double precision and to be natively x64 bit. We simply cannot keep the level of gameplay we are creating without making this particular conversion. Another change was the 32 bit depth buffer update (Cryengine uses 16bit natively). This gives us the ability to render now to a distance that’s never been seen before,.
There are many other challenges including the seamless transitioning, large scale multiplayer, economy system and AI combat to name a few.
DSOGaming: Thank you very much for the interview, any last words you want to share with our fans?
Sean Tracy: This game is not meant to be like other games on the market. First we don’t have a publisher, our publishers are our fans! Due to this we can do things that are completely unique and novel which should remind fans of a time when games were less derivative of each other and more of a unique experience that was truly memorable.
We really look forward to delivering the game to the fans! Fun times ahead.