Frictional Games Tech Interview – CPU Multi-threading, Chromatic Aberration, HPL Engine Tech Details

A couple of days ago, we had the pleasure of interviewing Frictional Games’ co-founder, Thomas Grip. Thomas shared some details about the engine powering their latest horror title, SOMA, as well as the game’s inspirations, its CPU multi-threaded capabilities, and whether there will be an option to turn off Chromatic Aberration. Enjoy the interview after the jump!

DSOGaming: Before we begin, please introduce yourselves to our readers.

Thomas Grip: My name is Thomas Grip and I am Creative Director at (and co-founder of) Frictional Games.

DSOGaming: SOMA will be powered by the HPL Engine. Can you go into more tech details about its graphical features? (Parallax Occlusion Mapping and Screen Space Reflections support, ambient occlusion, tessellation, etc.).

TG: SOMA will be powered by the third iteration by our internal engine. I think that the biggest changes from the previous version (that powered Amnesia) are:

– HDR Lighting
– Terrain support
– Much more powerful script support.
– Streaming

As far as graphical features goes, I do not feel it is worthwhile bringing attention to any. We have few new fancy stuff,� like new SSAO system and Spherical Harmonics based GI, but on the whole it is nothing that doesn’t exist in other engines. We do our best to make it all look as good as possible, but it is hard to have stuff you have not already seen in the other big engines. Our competitive edge is to have a very streamlined production pipeline and an engine that is heavily designed around it.

DSOGaming: Can you share more details about the game’s lighting system? How many simultaneous light sources will there be? Will there be any Global Illumination effects and if so, can you share more details about your GI solution?

TG: As mentioned there will be a bit of GI, but other than that it is just standard stuff. Peter, who does pretty much all tech these days, has done lots of great stuff, but a lot of it is not things that are easy to point out. A lot of it is under the hood features, that is crucial for pipeline and stuff like that. As for how many lights and stuff like that, it is highly dependent on what system you are aiming for, what sort of FPS you can deal with and other aspects of the scene in question.

DSOGaming: If you had to choose one, what would be the graphical feature – in SOMA – you are most proud of?

TG: I think the streaming is really nice. Previously we have had long load screens but know you just go from one level to another seamlessly.

DSOGaming: Shadows are essential for games like Amnesia and SOMA. Will the game feature a fully dynamic lighting and shadowing system? Can we expect all light sources – like flashlights and environmental lights – to cast dynamic shadows on all objects?

TG: Yeah shadows are really important to us, but it is still very expensive, so we are trying to be careful where we use it. That said, what we got, we make sure to use as good as possible.

DSOGaming: Both Penumbra and Amnesia had some really interesting physics-based puzzles. Can we expect more from SOMA and if so, have you tried to push the envelope of the game’s physics-based puzzles?

TG: Physics based puzzles have not been a major focus since the goal of SOMA is not puzzles, but to give the feeling of being inside an interactive narrative. Instead we have put effort into making interactions smoother and stuff like that. Having nice interactions with the physics is crucial for making the world feel believable and we try to make it possible to interact with as much of the world as possible.

DSOGaming: Will SOMA take advantage of more than four CPU cores as well as SLI/Crossfire systems? Can you talk a bit about the CPU scalability of the HPL Engine?

TG: A lot of work has been put into using multithreading as much as possible. Our previous versions we all single threaded so it has been a ton of effort to make it all work. We are not 100% were I would like us to be in terms of data driven design, but it is tons better than anything we have had before. When you make new iterations of an engine you always need to juggle redesigning the system and making sure everything works during development. So in the end we manage to get this side of the engine better than I thought we would.

SOMA - Gameplay Trailer

DSOGaming: Lately, we’ve seen titles suffering from noticeable pop-in of objects. While some games have higher LOD levels, every game – more or less – suffers from it. What’s really puzzling us is that while dynamic tessellation basically solves this problem by varying the level of detail on the fly, no one has ever used it. What’s your opinion on dynamic tessellation and have you experimented with it in order to eliminate object/environmental pop-ins? Also, what’s your LOD solution in SOMA?

TG: Our environments are all closed quarters or with a short viewing distance that this has not really been an issue for us. We simple cull distant objects to get some extra performance and it is pretty much never noticeable. We were planning on using tessellation to get detail offset mapping on the terrain, but we ran out of time to update the art to support it. It is in the engine though, so modders will be able to play around with it.

DSOGaming: SOMA’s environments reminded us of those in Doom 3 (which is great in our books). Did that game’s levels inspired you? If not, what video-games were your inspirations for SOMA’s environments?

TG: One big inspiration that we took from Doom 3 is its terminals. I loved how they felt part of the game world and how immersive it was to use them. In SOMA is a lot of different ones from the player to find and mess around with and is a big part of the game. They work pretty much the same way as in Doom 3 expect that you need to click one before you can interact, but otherwise it is very much the same.

SOMA has been inspired by a ton of games, for instance:

– Bioshock. I just love the first 20 or so minutes of that game, the narrative just unfolds in a such a great and immersive way.
– Spec Ops: The Line. The way they handle moral choices in an analog fashion has been a big inspiration for how we handle ours
– Silent Hill. The way in which you get to play through horrific scenarios, and not just watch cut-scenes, is a big influence.

There is a ton more of course, but those are some of the bigger ones.

DSOGaming: What’s your opinion on DX12?

TG: Afraid I know too little about to give any comments. We still use OpenGL 🙂

DSOGaming: Lately we’ve seen a number of games forcing Chromatic Aberration. Will SOMA feature Chromatic Aberration and if so, will there be an option to turn it off?

TG: We will feature it as an effect during certain parts of the game. You can turn it off if you really want to though.

DSOGaming: Thank you very much for the interview, any last words you want to share with our fans

TG: We have spent 5 years working on SOMA and honestly think it is our greatest achievement yet. The way in which the game sets it apart from our previous ones (and really other horror games on the market) is by a very tight focus on certain themes like identity, subjective experience and AI, and how the game revolves around them. In our other games the subject matters have been more slapped on, but here they are part of the game and integral to the horror experience. So while you will get a share of scares from being hunted by various nasty creatures, the real terror will come from directly confronting these themes. SOMA is not made to be all about jumpscares, but to be a deeply psychological horror that stays long after playing. It has been really hard to get right and we are extremely excited to hear how people experience it all!