An Over Overview of VR Locomotion Types
One of the biggest challenges facing new VR developers is locomotion. How best to let your player move around without feeling sick? Some of the approaches we've seen emerging include:
Some experiences don't have any artificial locomotion built in- the room size is the room size and you can move around freely within those boundaries. Games like Hover Junkers have taken this approach and run wild with it.
Placing the player in a cockpit is a tried and true method for seated experiences. While we've seen these largely used in space and driving games, we're using a cockpit approach for our story adventure game Life of Lon.
There are other approaches being worked on of course, but these are emerging as some of the most popular.
Budget Cuts has a unique approach to locomotion that will surely find its way into other games. By throwing portals, a player can navigate rooms and hallways without moving very far in the play-space.
THIRD PERSON LOCOMOTION
Third person games are starting to find their way to VR devices- and this brings with it a number of approaches for third person. First off, we have the fixed camera approach used by Gunfire Games with Chronos:
Next up we have the following third person approach used by Oculus for Lucky's Tale:
Which approach is better for VR? They both seem to have their strengths and weaknesses. With a fixed camera, the player could be put into awkward situations during the camera shift, and with the moving camera, there might be nausea issues depending on how well the camera is implemented. Considerations worth thinking about.
There are a number of approaches to blink locomotion- but the gist of it is that there is a blinking effect and the player is moved or turned without any animation. There might be a fade out and in effect, or it might be instantaneous. The player might be able to create a portal, or be able to choose where her avatar will move to and which direction to face.
In a hybrid scenario, multiple types of locomotion might be combined to form some new method. For example, an experience may have a seated cockpit but also a standing room-scale component. In Life of Lon, we have a largely cockpit-type experience but we've incorporated blink locomotion into the control scheme. In the future, we'll surely discover new and interesting ways to get around in VR either through the use of new peripherals, or through new ways of thinking.
Locomotion in Life of Lon
Life of Lon is a Journey-esque story game that will have you traveling across long distances taking in beautiful vistas and solving challenging environment puzzles. We originally planned it as a sidescroller that took place largely under water. Initially, the player (playing as a young cosmonaut named Lon) would swim around in his space suit. When we switched to VR, we had to rethink our most fundamental interactions. How were we going to let the player move around under water, and what if they started to feel sick?
Our first tests into this kind of locomotion made us feel quite ill, so we knew we needed to do our homework.
The first thing we learned was that the player needs some kind of stabilization mechanism to give them an equivalent to the horizon. Enter the Stabilization Semi-Sphere.
The Stabilization Semi-Sephere (SSS)
When we were designing Lon's ship, we tested a design where the player would be facing outward looking through a large portal. This resulted in a great deal of simulator sickness. What we discovered through much iteration is that if the ship was turned on its side, a natural horizon line was created around the player- giving her the sense of stability she needed. Once we discovered this, test after test returned an incredible reduction or altogether elimination of nausea in our play testers.
We took this learning and applied it to our underwater areas and found that similar results were achieved. We created a glowing semi-sphere that encloses the player while moving around. Nausea was all but eliminated in most players. For the ones who still felt nauseus, we spent a lot of time refining our comfort controls.
Comfort Controls, Not Just Comfort Options
A lot of devs that are building for VR are putting comfort controls into their options. We think this is a fantastic idea, but we wanted to take it a step further. What if you could enter comfort control mode without going into a menu? Why not integrate it into the primary controls somehow?
What we ended up with is a hybrid approach that utilizes the entire controller. For players that wanted trigger button locomotion, we give them the ability to press R2 and L2 to turn or R2+L2 to go straight ahead. For players that needed to lean into their turns to give their inner ear a sensation of movement, we've integrated tilt to turn controls. If the player is holding down A or R2+L2 and leans, their craft will turn in that direction- more sharply depending on the amount of lean. And finally, we use the D-Pad for blink locomotion. D-left and D-right turn the craft at certain intervals without animation, and D-up and D-down move the craft forward and back without animation. We may yet tweak these controls for the final game, but this is where we've ended up at the time of writing this article.
Bringing it all together
Have a look at our first trailer to get a sense for how we've taken these principles and applied them to Life of Lon:
Have Your Cake and Eat it too
Game devs need to ensure that power is given to the players when it comes to comfort. Being able to change your control configuration on the fly gives players the absolute best chance to play your game comfortably because they can switch back to comfort controls during sequences they deem too intense. We recommend giving this hybrid approach a try.
Did you give this approach a try in your game? Leave us a comment and let us know how it turned out!