Cloudhead on Locomotion in VR

Cloudhead Games has some great ideas about locomotion in VR in this video.

This video brings up a couple of interesting topics worth discussing a bit more.
The first is about some details of the chaperone system. The Cloudhead guys discuss how they are showing some hints in game about the bounds of your real world space and I thought it would be interesting to discuss that in the context of the overall system.

Chaperone exists first and foremost to help people feel comfortable about moving around in room scale VR without having to worry about hurting yourself by running into something in the real world. One interesting aspect of this is that the chaperone system can really help the feeling of presence because once you get used to it you feel much more free to move around in your space. We do a ton of play testing and demos and pretty commonly see the first couple of minutes people move around with a lot of hesitation but once they get comfortable they let the experience they are in take over.

Within the chaperone system we think of two boundaries. The hard-bounds are the real limits of the physical space. If you are in an empty room, that would be the walls. If the room isn’t empty it might be some artificial line that represents the furniture. But the point is hard-bounds are real “do not pass” line. Hard-bounds are implemented in the OpenVR system and when the player gets near them we will draw the shape of the room over anything the current experience is drawing right in the compositor. This is actually somewhat intentionally presence breaking. If you are about to collide with something we want to bump you out of the immersive experience right away.

We also tried experimenting with using just a partial wall in front of you for the hard-bounds to tone it down a bit. I didn’t like that approach much because once I was getting into those limits I really wanted to see the shape of the whole room to help reorient myself.

Soft-bounds however are another matter. Soft-bounds are another set of lines inset a bit from the hard-bounds and they really represent the space you should be inside most of the time when playing. When you are standing inside the soft-bounds, you shouldn’t be able to easily wack things outside the hard-bounds. Soft-bounds aren’t drawn by the system because we don’t have a good way to do it automatically and keep you immersed in the experience you are in. However each experience can ideally represent the soft-bounds in some way that is consistent with its own look and that doesn’t really disrupt your overall presence. One great example of this is TheBlu from WEVR. You are standing underwater on the deck of a ship and its safe to walk anywhere up to the railing in one direction and up to a bunch of junk and wires in the other direction. If your play-space is smaller they could pretty easily move the junk and wires so that the clear area of the deck still represents the safe space. Other games might need to use things like subtle glowing lines on the floor (as seen in the Cloudhead video).

So the key is- use subtle cues to give the player hints about the right place to play. And when they move outside those limits give them less subtle warnings to keep them safe and help reorient themselves in the space.

The Cloudhead video also shows some great ideas about dealing with virtual walls. Obviously in VR you can’t prevent the user from moving the camera into some object just because its supposed to be solid in the virtual world. Remember that the camera IS their head, so if they move their head you have to move the camera. But it doesn’t mean you can’t do something about it. Now, sometimes its pretty fun to just let people put their heads inside your geometry and see the cool insides (people do this all the time with the robot in our Aperture demo and its a lot of fun). But if you don’t want to allow that you can either blur or fade the world when they put their head into the object. I especially like the Cloudhead solution of teleporting you back to some safe place if you stay in there for a while- the problem with just fading or bluring is it can become disorienting to not have that visual reference so it can be uncomfortable or actually difficult to find the correct direction to back out.

Finally I have head some reactions to the video of people expecting that the teleportation for locomotion will diminish presence. I’m sure this varies a bunch from person to person but for me at least it ends up very natural. Its hard to describe but after using it for hours I end up actually teleporting around fairly quickly and my brain doesn’t even think about it that much anymore. In contrast when I try a VR title that moves me around by gliding it feels very unnatural- something about the smooth motion seems wrong (and then I get sick and things feel even more wrong.. )

It all goes back to part of what is so exciting about working on VR right now- no one really knows the right way to do all this stuff. The space is wide open for people to come up with new ideas and test them to see what really works.

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