
Tricks Make Virtual Reality Feel Real (2016) - dnetesn
http://nautil.us/issue/32/space/these-tricks-make-virtual-reality-feel-real
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DanAndersen
Real-time graphics in general, not just VR, has always had "tricks" at its
core. What has drawn me to that subfield of graphics is I think the collection
of 'hacks' and deceptions that are needed for the user/viewer to buy into the
virtual environment, whether on a desktop screen or in an HMD. There's an
aspect of cleverness about it all that I enjoy -- from billboarding faraway
objects instead of rendering them as 3D to baking static shadows into textures
before runtime.

I wonder if there have been any in-depth articles examining comparisons
between real-time graphics and stagecraft. The design of props and backgrounds
in the theatre has similar objectives -- not necessarily fooling the audience
into thinking it's real, but using a collection of 'tricks' to extend the
capabilities of the stage to achieve greater effects. When attending a
performance of The Nutcracker a few months ago, I found myself fascinated by
how the multiple layers of forced-perspective backdrops offered a greater
sense of depth to the stage.

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kristiandupont
Reading the source code of a 3D engine can be similar to having a magic trick
explained to you. At least, the first time I did, I found it quite
disappointing or anti-climatic: oh, so this actually only works if you see it
from this specific angle and you cannot move that light in real time, there
are just two of them, ...

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DanAndersen
There's a similar anticlimax when looking at the big flashy publication videos
at graphics conferences. Some new technique looks absolutely amazing, then you
start to notice the hand-picked best conditions shown in the video (oh, this
method only works in static scenes, when there's no motion blur, etc etc).

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Animats
Now that's a useful article. Unusual for Medium. It even has citations.

Those tricks are used commercially in the "Star Wars Experience" at
Disneyland.[1][2] They use a custom-built real-world space which is much
smaller than the virtual space the players think they're in.

This isn't going to work in your living room, unless you have a really big
living room. But it could work in a classroom-sized room, or a storefront-
sized room, or a back yard. You don't need a gymnasium-sized room.

To make this a mass market product, it needs to work without a custom space.
The VR gear needs to be able to detect obstacles in the real world. It needs a
depth camera. Not much range is needed, maybe 4m or so, enough to detect
anything you could run into, trip over, or fall off. The second generation
Kinect would probably work.

Real-world obstacles need to appear in the virtual world when necessary, even
if it breaks the illusion. If there's something you could trip over in the
back yard, that has to show up in the VR world. Worst case, the system dumps
the VR world entirely and just gives the user an unmodified view of the real
world. This isn't augmented reality, which is reality with a little VR added.
It's VR with just enough real world added for safety.

The technology used for the Star Wars experience costs about $10,000 per
player. That has to come way down without degrading the experience quality.

[1] [https://disneyland.disney.go.com/attractions/downtown-
disney...](https://disneyland.disney.go.com/attractions/downtown-disney-
district/star-wars-secrets-empire/) [2] [http://www.businessinsider.com/star-
wars-secrets-of-the-empi...](http://www.businessinsider.com/star-wars-secrets-
of-the-empire-the-void-vr-experience-disneyland-photos-2018-2)

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chimprich
> This isn't going to work in your living room, unless you have a really big
> living room.

I don't know about that. Unseen Diplomacy [0] uses similar tricks to simulate
a much larger space than the size of the room. It requires a minimum area of
3m x 4m, which is within the size of many people's rooms (admittedly, I only
managed to find this much space when I temporarily had no furniture in the
room). It's quite an effective experience.

[0]
[http://store.steampowered.com/app/429830/Unseen_Diplomacy/](http://store.steampowered.com/app/429830/Unseen_Diplomacy/)

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dwighttk
Unseen Diplomacy is really cool... Its tricks are also not going to let you
play Skyrim like you are in a holo-deck.

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dwighttk
That redirected walking video was weird... The guy walked what looked like
about 10 feet forwards in VR and went what looked like twice as far in the
enormous room that was at least 4x too small to get him to walk in a circle to
continue the straight line...

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tgb
Related: in [1] there's a VR version of the hyperbolic plane where there's
"more space" than the Euclidean space we live in. So the person in the demo
walks a loop and a half in order to end up back where he started in hyperbolic
space. That group has some talks filmed on youtube that explain it in more
detail if you want to listen, but I can't find the right snippet.

[1]
[https://www.youtube.com/watch?v=T7p-VgAWlao](https://www.youtube.com/watch?v=T7p-VgAWlao)

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stephengillie
I've been wondering if inertial engines could be placed on either side of a VR
helmet, to combat motion sickness. When your VR avatar would be moving
forward, the inertial engines would both pull backwards, hopefully tricking
your inner ear. This could be extended to make all motion feel more natural.

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cjsawyer
Can you further explain your “interial engine”? My understanding of physics
says that it would only be able to actuate once then slowly “reset”, ruining
the illusion if you’re moving in any steady state mannor

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stephengillie
Gyroscopes are used in satellites to change orientation. It should be possible
to use one on either side of the head to simulate basic balanced inertia.

[https://en.wikipedia.org/wiki/Attitude_control](https://en.wikipedia.org/wiki/Attitude_control)

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cjsawyer
Ah. I was thinking linear inertia and you were describing rotational.

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Barjak
Of course the omnipresent Gwern makes an appearance in the comments.

