Prelude:
The reason I wanted to post this guide is because I see this game as being an essential experience on the Index and yet so many people dismiss Subnautica for performance reasons or for not supporting hand tracked controllers.
Update 6/28: I now have my index and there are a lot of weird smearing and visual anomalies with the index that are unique to subnautica. I'd say wait for driver updates but it's not unplayable if you can't.... It's literally day 1 and to be expected.
VR can be used for a lot of things and one of them is really deep, impactful experiences in other worlds that you can play for hours (potentially seated) comfortably. Nothing fits this description better than deep sea diving in an open-world alien ocean with over 50 hours of content as well as crafting, survival, and underwater sea-base building systems. It also has an active day-night and star system cycle with two very different sized moons and a sun. You can witness beautiful sunrises and sunsets and you can even see the bigger of the two moons occasionally cause a solar eclipse out of nowhere. It's chilling; it's visceral; it's gripping and it's one of the best games I've ever played in VR.
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No the game won't make use of the Index controllers, but, it will benefit hugely from the headset for several reasons:
Resolution and Display Quality - It's an extremely beautiful game so any optical features will really shine and because it is a bright game LED isn't going to matter. It will greatly benefit from edge to edge clarity and more FOV because a lot of the GUI elements and world always feels unfocused on the edges and the immersion factor is very high already but the closer you can get to the lenses the better.
Refresh Rate - I'm fairly certain running the game in 120 with a bit of motion smoothing at 60 will make for a more "solid" and comfortable experience for the longer play session a game like Subnautica is made for. Will update once I get my Index on Friday :)
Ergonomics and Comfort - Finally the great ergonomics of the Index, such as the speakers not touching your ears, and better materials, will probably bug you less after an hour or so like other headsets and will allow for extended periods of play time where you can really get lost in VR.
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To do it right you'll need:
A swivel office chair and an xbox controller - Some people like mouse and keyboard but it's more comfortable and "VR"-like to be able to turn the chair in any direction and use your head to look around. Once I have my Index controllers on Friday I will try to see if I can bind them in a way that makes sense. For now I recommend an xbox controller. *Optional: To really get it right a retractable leash cable management solution so the cable comes from the ceiling and stays out of the way and doesn't annoy you.
A higher-end computer - I recommend a nvidia gtx 1080 and an intel 6700k as a baseline for a good experience on the Index. Higher up will allow you to take advantage of higher refresh rates. *Full Disclosure: I wrote this article with a 2080ti and 7700k but I was able to get the game running smooth on a 1080 as well. You may have to down sample a bit on the 1080 depending how much reprojection you can handle.
SSD - If you don't install this game on an SSD you'll never be able to make it smooth. It does a ton of writing and reading of JSON files to maintain your state verse the original state of the game. There is something you need to do with the ProgramData folder on your OS drive below also.
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And follow these steps for a smooth experience (and don't follow these ones which you may have found on youtube):
Medium graphics for water and details - Medium details is *critical* because the game has hidden texture settings, 1-4, where high will put the game on 4. Unfortunately setting 4 is too much for the Unity engine to handle at 90 fps and no amount of hardware power will get around the basic limits of the engine. A 2080ti won't do you any good. You can't see this texture setting in VR but you can get to it in the flat version by hitting f3 and then f8 in the main menu or installing this mod (which may have compatibility issues so to be safe just go medium details). You could probably do high water but it'll reproject every time you go up to the surface and the medium water looks pretty snazzy IMO. You can go high for AA - I recommend high TAA. I would leave ambient occlusion on low and shadows on medium or low.
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Set the flat version resolution to 1080p or 720p or even lower - I think there is a bug where the mirror settings can be ignored and it will mirror at the resolution of whatever the flat game is in. Sometimes it seems like settings in the flat game will override settings in the VR game. So if you think you may have changed something while playing flat, reset everything to defaults (in flat) and make the graphics and resolution to what you would in VR or lower (and the resolution of what you would want the mirror screen to be). I'd say for performance just do everything on low in the flat version and a resolution of 640x480.
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CPU advice and FPS increase mod by Panj- I'm not 100% sure this is necessary but I took this step. It should allow a higher threaded CPU (8+ threads) to use more threads to process Subnautica. I tried several things with my processor including overclocking, disabling hyper-threading, and this mod. The most noticeable thing was OCing my processor a good 8%. It still was only being used at like 67%. I think the mod may have bumped it up a bit (may have been 50ish before?). Don't disable hyper-threading it won't matter. Honestly just get rid of your other programs and if your computer has gotten slow, back it up and reset it fully (fresh install). Nothing beats the performance of a freshly reset PC and right before getting the Index is a fine time.
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ProgramData folder permissions - This is like the dumbest thing. Apparently the developers created a cache in this system critical folder that is meant to hold configuration data, not state data. The game reads and writes to it all the time and soon as you load a game and the security of the folder is causing slowdowns. This change *WORKED* for me and is an essential part of this guide. The issue is fully described here and the fix is by the TheTool Jun 17, 2018 @ 7:47am. Replacing C with whatever folder your OS is installed in, click properties for the folder 'C:\ProgramData\Unknown Worlds\Subnautica'. Click the security tab. Edit it and check everything so that all users have full access. Then click advanced and try to do the same thing. Just give everything permissions for this one folder. *If you don't have your OS on an SSD and Subnautica on an SSD, this will not work. Having ProgramData and the Subnautica directory on different SSDs is fine however.
Super Sampling and Refresh - Do this last but try 1.0 SS on the Index (=~ 1.77SS on Vive OG) and work your way down until you reach a balance between resolution and a solid refresh rate. With a 2080ti I can easily do 1.3 SS but I'll probably put that into 120hz and bring it back down to 1.0SS. You could easily try 80hz to see if that makes 1.0SS more obtainable. It's worth experimenting with various sampling and refresh rates.
It's sort of the game - It's not nearly as bad as fallout 4 but there is going to be a little hitching during pop-in sequences as it loads more ocean where there will be some reprojection. The unity engine isn't ideal for massive open world games. But it should be relatively smooth on a powerful machine with these tweaks. In a way that was never obtainable in FO4 and is very comfortable and enjoyable.
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Then we still have to fix the bad vr implementation:
Fix the crappy VR implementation. There are a host of issues with the stock VR implementation including the camera in many situations, missing animations, the inventory screen being too close etc. Thanks to WhoTnT, who created an incredible mod, we no longer have to deal with any of these and can play the game from start to finish with few issues. First get QModManager to allow mod installation. Then install the VR Enchancements mod. You can also make walking on land faster which was hilariously slow in VR. This can now be found in general settings in-game. I also recommend checking "enable VR animations". Some of them might cause motion sickness but they are pretty great. Specifically if you get into a>! certain alien warp portal in the mountain alien base and you start flying all over the place maybe just close your eyes and wait it out for a few seconds.!<
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OpenVR Advanced Settings: This will probably be updated for the Index soon I would imagine. Download this program and install for SteamVR. It'll allow you to do a ton of things but we are interested in being able to have less chaperone (or none at all), have an orientation square on the floor, and being able to change the y position. With a seated game I've found that you don't need chaperone on at all; you only need an orientation square on the floor. To get this floor marker simply go to the advanced settings menu -> chaperone settings and check the center marker box and then make the chaperone invisible (if you'd like) by moving the visibility to 0.
In-game you may run into camera and orientation problems. You can reset the camera orientation with the f2 key. If your height is off you will need to use Advanced Settings to change the y position to raise or lower yourself. A typical use case is you restart the game and you are taller than usual so you keep clipping into ceilings. It's also super useful for aligning yourself properly in vehicles.
Normally it just works out as long as you start the game with the headset on how you intend to play (or f2 with the headset where and how it is going to be played, thanks lambomang).
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Other Great Quality of Life Mods
- Better Scanner Blips - Once you get a scanner room this will make using it in VR so much better, trust me.
- EasyCraft - Is this game Aquatic Organizer or Subnautica? This mod allows you to use resources near by that have already been collected to craft without needing to have them in your limited inventory. Spend that extra time exploring the amazing ocean. Crafting is still just as fun this way.
- BetterSprinting - Hold the analog stick down to sprint? Really? This makes it toggle-able.
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*Full Disclosure - I have nothing to do with the Subnautica team and I'm not benefiting from this post in any way, just a huge fan.
