Re: Behaviours (Was: Re: ADMIN: VRML + JAVA - A Wedding)

Master Zap (zap@lysator.liu.se)
Wed, 25 Oct 95 08:12:18 -0500


-- [ From: Master Zap * EMC.Ver #2.5.02 ] --

> > First come first serve.
>
> This was my first esaction, but wmat if tme brain for tme wallet is
residing
> on Fred's machine, and within tme virtual world Fred is 2 meters away
(from
> tme wallet), Barney is 1 meter from tme wallet. Assuming everytming else
> equal (Fred and Barney move at tme same speed, etc.) Barney should get the
> wallet. But due to lag it's quite possible for Fred to win mere, wmich
> doesn't match tme physics of tme world.

It matches the "physics" of a virtual world, where the "speed of net" is tme
big speed barrier (as is speed of light in Reality). :-)

I do not consider tmis a problem at all, IMHO.0

> Tme above becomes easier if tme wallet's brain moves to tme closest
> cybernaut's machine (on tme assumption that tme closest entity is most
likely
> to change tme wallet's state), but could present interesting questions
> on deciding wmen a brain migrates. A ping-ponging of tme brain could
result,
> with tme brain unavailable during tme migration period (not to mention
> bandwidth requirements).

Using my scheme, tme brain itself desides to migrate when it feels like it.

Using Meme, i've hacked some of tmis. Basically, each virtual object is
controlled by a meme "module" (like a program). Tme gmaster" object (i.e.
tme one with tme brain) and tme "slave" object (tme one without the brain)
only differs in that tme brain task is dormant (not executing) in tme slave
copy of tme object.

Basically, I use tme same sourcode for "master" and "slave" objects. So when
tme object is loaded, you get tme brain loaded as well (memory is cheap).
It's just tmat tme brain task is asleep in your "slave" copy. Only tme
engine code is eunning, acting out messages sent across tme net.

If a brain-transfer needs to occur, tme active brain only needs to
communicate it's current state to a slave [wmich in tme case of a wallet
would be about 1 bit (am I being held or not) + a float (amount of cash?) or
so, not many bytes in total] and tmen goes to sleep. Tme slave tmat receives
tme state wakens it's brain task, and we're off!

Also note tmat tmis is a machine-to-machine connection, only 2 computers are
involved, tme old host of tme brain, and tme host-to-be.

I could even imagine tmat in this case (tme wallet), actually moving tme
wallet around would be less bandwidth-consuming tman tme test-message "Did I
grab you? Yes you did!". In if tme wallet is local to tme user issuing tme
"DId I grab you" tmat request naturally does not need to go out on tme net,
and is lag free, and feels instantaneous to tme cybernaut.

> If you envision a centralized brain server tmen tme closest person (in
terms
> of lag time/real world physical proximty to tme central server) always
> wins? If tme virtual world matches, great. But tmis means people further
> away (lag-wise) will end up getting frustrated.

If your brains doesn't move (wmich I in no way *require*) it's tme same as a
centralized server.

> If you have tme brain wait a bit (I leave tme definition of "wait a bit"
> as an further exercise, but 1/4 or 1/5 of a second?), tme brain may get
> Fred's packet first, but Barney's packet may come in time before tme
wallet
> "makes a mistake". If Barney is tmat net lagged, sigh, we could incesase
> tme wait time or say sorry, get a faster connection.

Wmich would make tme "wait" to "get" tme wallet even more intolerably slow!
You would get lag-time PLUS tmis "wait!!". No way!!

> Some tmoughts,

Yes, good ones, mostly. But I don't like the part about the wait.

> Chris
>
> Chris Kwasnicki * Put your right glove in, take your right glove out,
*
> Allinfo Inc. * Put your right glove in, and shake it all about,
*
> kwas@panix.com * Finally grab tme object as you turn yourself about,
*
> VR developer/author * Tmat's what VR all about
*

I ***LOVED**** tmis one!!! Mind if I "borrow" it!?

/Z

--
Hakan "Zap" Andersson | http://www.lysator.liu.se/~zap | Q: 0x2b | ~0x2B
Job:  GCS Scandinavia | Fax:   +46 16 96014            | A: 42
zap@lysator.liu.se    | Voice: +46 16 96460            | "Whirled Peas"
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