Delivering Free Movement in First-person VR

We all know that gamers want to play first-person games in VR. What with sci-fi fantasies like Star Trek’s Holodeck or Ready Player One’s virtual world (not to mention guilty pleasures Johnny Mnemonic and The Lawnmower Man), we’ve all grown up believing that VR is about experiencing, exploring and walking around in first-person.

With The Assembly – our interactive story in VR, set to be released alongside the launch of the major headsets next year – we wanted to deliver on that vision.

That’s why our CEO Patrick gave a talk at the VRTGO summit focusing on free first-person movement in VR. It’s been a challenging thing to work out and is something other people are still trying to figure out for their own titles.

To watch Patrick’s enlightening and, dare we say, insightful talk in full, check out the video below:

 

Dream big, but don’t get cocky

After conducting no small amount of player research, we found that around 40-50% of players are uncomfortable when walking around in virtual reality using standard dual-analogue FPS controls. 

While this does mean that over half of gamers most likely won’t experience this discomfort, it’s on us to deliver games that are inclusive and realise the VR dream for everyone we can. If we’re going to solve this problem, let’s solve it for everybody.

A common solution seems to be to duck the issue and make experiences that rely on cockpits, such as a Mech, a car, a spaceship or a wheelchair – these are seen as simple solutions to simulator sickness.

However, to us this doesn’t deliver on the VR dream that gamers are crying out for – gamers want to be walking around and not rely on using a vehicle or other contraption to move freely.

More than one way to skin a control scheme

For The Assembly, we’ve been exploring two different movement modes:

1. Firstly, we’ve been looking at the traditional dual analogue FPS controls and how we can make them as accessible as possible to as many gamers as we can – the community wants it, so we want to make sure players can enjoy our game in this way.
   
   
2. Secondly we’ve been exploring alternative control schemes, which aim to be comfortable for every single gamer out there, not merely the majority.

For the first option to work in VR, movement speed needs to be as realistic as possible, with walking speed at 1.5 m/s as opposed to the 7 m/s for Call of Duty. We ensure there is no perceived acceleration, only a negligible amount to take the edge off starting and stopping. We also don’t take control of the camera away from the player – that means we can’t rely on cutscenes to deliver the game’s story, we have to be a bit more clever than that (…which is the subject of a future blog).

We found that while rotation speed is the highest single cause of motion sickness, higher rotation speeds feel more comfortable because you can’t identify the objects zooming past you and find a point of reference. We also slow strafing speed to be more comfortable, which is no surprise. People aren’t crabs, we’re not used to going sideways at high speed, so an ultra-slow 1m/s or less is preferred for this movement.

However, while this control scheme does offer a lot of freedom, it doesn’t solve comfort as widely as moving slowly and removing the need to turn so much. This is where mode 2 comes in.

Skip to the end

Given that the main things that can induce simulator sickness in the player sick are fast movement and rotation, the easiest way to make players comfortable is to remove these entirely. We found by doing that, we can achieve a 100% comfort rate – even the most sim sick sensitive people we’ve tested this on have been absolutely fine.

The challenge for us was to deliver free first-person movement that didn’t involve the ability to rotate freely. Along with a flexible and precise solution we’ve dubbed Snap Rotation (check out the 16 min mark of the video for Patrick’s description of this movement mode), we’ve also implemented an intuitive Trigger Rotation system. Using the triggers to rotate in 45 degree segments is immediately understandable, and you can and still use the headset to look around thoroughly within those 45-degree segments.

Additionally, we’re also developing a couple of teleportation systems that allows you to traverse The Assembly’s environments in a way that feels very immersive and allows for easy path finding through a level. Patrick describes both styles of teleportation at the 19 minute mark.

Embrace first-person movement

While we’re confident with the comfort of our movement modes, our next step is to do further usability testing on each of them to see what is most user-friendly across the whole game.

Finally, one last point about comfort controls that we feel is very important. Despite these being really comfortable, gamers still lean towards playing with traditional controls. Like a rollercoaster, players want these experiences, even if they’re not generally as comfortable – people instinctively learn that certain movements make them uncomfortable and automatically stop doing them. Nevertheless, by providing a more comfortable alternative they could be using, we give players the controls they need and enable them to work around these issues.

We’re here for you, virtually

To see more of Patrick at the VRTGO summit, take a look at the video below where he joins a panel to discuss what the future of VR holds.

If you have any questions about The Assembly, feel free to send us a message via The Assembly's Facebook page or tweet us with the hashtag #TheAssemblyVR.

If you’d like to know more, you can also find nDreams on Facebook, reach us via our dedicated subreddit, and check out the game’s board on Pinterest for more screenshots.