The schome community Go to the Schome Wiki
February 25, 2020, 04:07:50 AM *
Welcome, Guest. Please login or register.

Login with username, password and session length
News: To register for the wiki or forum email ONE sentence explaining why you want to join the Schommunity to Peter[dot]Twining[at]newcastle[dot]edu[dot]au
(Replace [dot] with . and [at] with @)
 
   Home   Help Search Login Register  
Pages: 1 [2] 3   Go Down
  Print  
Author Topic: Experimentation on breaking SSF  (Read 15129 times)
Katharine Berry


Email
« Reply #15 on: August 15, 2007, 06:26:08 PM »

That's the same general effect you'd get from mad physics stuff (which was probably the cause) - the number marked "Time Dilation" shows just that - 1.00 means that time (specifically the physics engine) is running at 1x normal speed. If that gets below 0.95 it'll be noticable, below 0.01 and the sim's dead. And you can't move (or, rather, you can, but do so really slowly).

Furthermore, high levels of physics engine activity may use up CPU cycles that could otherwise be spent monitoring network connections or accepting new ones, essentially logging everyone out and making it impossible to log in again until the sim detects it and restarts (unlikely by this stage), or Linden Lab manually intervene.
Logged
Marko Schomer
Moderator
Hero Member
*****


Posts: 631


View Profile Email
« Reply #16 on: August 15, 2007, 06:52:21 PM »

I stopped experimentation after the initial warning about the possibility of crashing. However, I'm not actually sure about the risk involved. Since the objects move apart immediately, and there's nothing to prevent them doing so fully, I would have thought the probability of serious lag would be extremely low.

I'm also unclear on what theories one can form about the act of throwing objects in odd directions.

My original investigations were into how strong the barrier against intersection was (and whether it was based on velocity, momentum, or other factors) Since there's evidently no such force in real life, it's quite interesting how one works in SL (the fact that it's not an absolute barrier is interesting in itself).
Logged
Explo Schomer
Moderator
Hero Member
*****


Posts: 2386


Nice, eh?


View Profile Email
« Reply #17 on: August 16, 2007, 01:51:22 PM »

That's the same general effect you'd get from mad physics stuff (which was probably the cause)

I believe the actual cause was the generation of thousands of little wooden cubes at once. If it was due to physics experiments you would notice it once, and then once the island came back online it would happen again slower, to work out what happened. ;)
Logged

'I am the gadfly'-or at least, I'd like to be

Question everything, including this.
Katharine Berry


Email
« Reply #18 on: August 16, 2007, 02:34:02 PM »

That's the same general effect you'd get from mad physics stuff (which was probably the cause)

I believe the actual cause was the generation of thousands of little wooden cubes at once. If it was due to physics experiments you would notice it once, and then once the island came back online it would happen again slower, to work out what happened. ;)

That very rarely crashes a sim (unless the cubes were physical), although it tends to bring down the entire grid (not hard to do, is it? :P), which, if LL knows who did it, will generally result in a permaban and being reported to the appropiate authorities for causing a denial-of-service attack - LL can fairly easily demonstrate significant losses from a few hours of downtime or unusable-service-time. If this is done on a PI repeatedly, the sim is liable to be confiscated due to the sim owner's negligence.

Since there's evidently no such force in real life, it's quite interesting how one works in SL (the fact that it's not an absolute barrier is interesting in itself).

It is an absolute barrier - it's seen as part of the object (as far as the physics engine is concerned, all objects are slightly larger than they appear). However, SL is notoriously bad at actually preventing intersecting objects, or objects passing right through eachother.

I stopped experimentation after the initial warning about the possibility of crashing. However, I'm not actually sure about the risk involved. Since the objects move apart immediately, and there's nothing to prevent them doing so fully, I would have thought the probability of serious lag would be extremely low.

It seems I misunderstood what you were doing, as that wouldn't cause any issue. But I maintain that meddling with the physics engine is a bad idea anyway.
Logged
Marko Schomer
Moderator
Hero Member
*****


Posts: 631


View Profile Email
« Reply #19 on: August 16, 2007, 06:03:57 PM »

However, SL is notoriously bad at actually preventing intersecting objects, or objects passing right through eachother.

Which, in effect, means that the barrier isn't absolute. :P

It seems I misunderstood what you were doing, as that wouldn't cause any issue.

Thanks for warning me anyway. I'd far rather miss a few experiments than crash a grid and risk Schome suffering for it. As to meddling with the physics engine, I think as long as the risk is very low then it's worth doing experiments. Otherwise what can be done is greatly limited, and you get a situation similar to that faced with health and safety in RL.
Logged
Katharine Berry


Email
« Reply #20 on: August 16, 2007, 09:08:14 PM »

Yeah, but here bad stuff actually happens, unlike Health and Safety. :P

I say this having crashed my own sim more than once.

Which, in effect, means that the barrier isn't absolute.

It's just as absolute as the object, and when that new physics engine (which I now get to discuss the implementation of with LL, having signed an NDA to say I can't tell you) appears, all this will stop happening anyway. :P
Logged
Dan
Hero Member
*****


Posts: 1242



View Profile WWW Email
« Reply #21 on: August 16, 2007, 09:41:18 PM »

Are you saying they're actually going to put in place a quality games-standard physics engine?
Logged

SL: Woop Superior (MG) / Woop Kamachi (TG)
RL: Dan
Katharine Berry


Email
« Reply #22 on: August 16, 2007, 11:12:01 PM »

I am. :P
Logged
Dan
Hero Member
*****


Posts: 1242



View Profile WWW Email
« Reply #23 on: August 17, 2007, 07:46:48 AM »

Thank goodness.  This has been one of the things that has long bothered me about SL.
Logged

SL: Woop Superior (MG) / Woop Kamachi (TG)
RL: Dan
mgaved
Hero Member
*****


Posts: 1164



View Profile Email
« Reply #24 on: August 17, 2007, 08:06:46 AM »

Send forth details as you get them.....  :)
Logged

Teen Second Life: Mark Sparker / Second Life: Redmark Hax
Dan
Hero Member
*****


Posts: 1242



View Profile WWW Email
« Reply #25 on: August 17, 2007, 08:12:59 AM »

I think with an NDA in place that's going to be difficult  :(  Same when I'm beta testing games, I want to put out details on my blog but can't until we're near the end and the NDA gets lifted.
Logged

SL: Woop Superior (MG) / Woop Kamachi (TG)
RL: Dan
Achilles Schomer
The Hawaiian Shirts
Hero Member
***


Posts: 1687



View Profile Email
« Reply #26 on: August 17, 2007, 10:29:45 AM »

a assume a NDA is a secrecy directive?
Logged

My posts are like buses...you wait days for a reply then they all come at once!
Marko Schomer
Moderator
Hero Member
*****


Posts: 631


View Profile Email
« Reply #27 on: August 17, 2007, 10:36:58 AM »

Yeah, but here bad stuff actually happens, unlike Health and Safety. :P

It's quite odd when worse things happen in a virtual world than in the real one. :P

when that new physics engine (which I now get to discuss the implementation of with LL, having signed an NDA to say I can't tell you) appears, all this will stop happening anyway. :P

Really? I thought Havok 2.0 would just reduce problems with physics, rather than eliminate them. If not, then the physics group will have to check current laws all over again.  :(
Logged
Dan
Hero Member
*****


Posts: 1242



View Profile WWW Email
« Reply #28 on: August 17, 2007, 11:49:12 AM »

An NDA is a non-disclosure agreement.  Common policy when getting good people to evaluate/contribute to some kind of development to sign one of these when they aren't directly employed by the company.  Thus in the case of Katharine and the physics engine or myself and the likes of Lord of the Rings online we would be chatting to working with the developers and/or testing the latest developments, but having signed a non-disclosure agreement cannot publicise any of the information we have.
Logged

SL: Woop Superior (MG) / Woop Kamachi (TG)
RL: Dan
Katharine Berry


Email
« Reply #29 on: August 17, 2007, 12:29:53 PM »

Really? I thought Havok 2.0 would just reduce problems with physics, rather than eliminate them. If not, then the physics group will have to check current laws all over again.  :(

Havok 2 was abandoned in 2006. New physics project. :P
Logged
Pages: 1 [2] 3   Go Up
  Print  
 
Jump to:  

Powered by MySQL Powered by PHP Powered by SMF 2.0.15 | SMF © 2006-2008, Simple Machines LLC Valid XHTML 1.0! Valid CSS!