Altering Body Perception in VR
Virtual Reality presents the opportunity to create entirely new worlds – ones which players themselves inhabit. An often overlooked consequence of this is the ability to recreate the player, down to how they feel. This sounds dramatic, but really is just achieving feature parity with most other forms of media. Any book read from a first-person perspective, most video games that involve an avatar, or movies told from a specific character’s point-of-view all put the player in a different body and life.
There are compelling reasons beyond narrative to alter a user’s body perception in VR as well. Scenes can be more carefully crafted when the constraints of user motion and viewpoint are clearly defined. Equalizing physical stats between all players can achieve far more “fair” gameplay and even make a previously unplayable experience accessible to disabled users. Players can also be equalized to avatars that are not human or do not have human proportions – gorillas, giants, various constructs of robot.
Over the last year and a half, among my other duties at Unity, I have spent considerable time developing and experimenting with a library that can alter a user’s proportions and their perception of them. Below you’ll find a talk I delivered about my findings and experience. But first, a few bonus quirks about body adjustment:
- Rig Scaling (the most commonly used form of player equalization in the wild) has a side effect of also altering a user’s speed; making the user twice as big makes them twice as fast. However, average human walking speed does not correlate linearly with height. A more accurate (and fair) model would involve slightly artificially slowing players that have been scaled up.
- Software based adjustments cannot affect the raw velocity data coming out of hardware trackers. Any kind of physics code for gauging force (such as throwing virtual objects) will need to be informed of scale changes and be adjusted accordingly.
- Extreme size changes can have a psychological effect – becoming tiny, like an ant, can give the user a sense of danger or unease. On the flip size, becoming gigantic grants feelings of empowerment. (I have personally felt both these effects, even in simple white box environments.)
The results from this development will be included in Unity’s XR Foundation Toolkit. I am excited to see what new experiences the community can build with these tools. VR is a young medium still. Do not accept limitations; find a way to surpass them.