HL2 Multiplayer Question (about physics and object/character interaction)

[Netherscourge]

Has it been stated anywhere if the objects in the game would do harm to characters if manipulated?

For example, say I am playing multiplayer and my opponent is hiding under a platform being held up by two or 3 boards. If I am across the room and shoot out the boards, would the platform fall on top of him causing damage? Or would it just fall? And would the falling platform react to the character's physics too? Or am I wishing for too much?

Just wondering. Having that kind of object/character interaction would really make you think twice about your hiding spots in a multiplayer game.

 

[hroo772]

Seeing that in one of the videos it shows a grenade being thrown under a container and it falling on the combine below suggests that it will be possible for that to happen. I guess anything is possible as long as you can code it. ;-)

 

[bate18]

good question, bump

 

[Non-Sequitur]

Yes, characters take damage from objects falling on them. More damage is done when the object has a higher weight value, also when it falls from a greater height.

 

[The Dark Elf]

Originally posted by EvilEwok
So i could camp on a roof and when somebody comes walking by i could jump and land on them and kill them?

But, will he break my fall or will i take dammage aswell?

I think deffinately possible to injure someone jumping on them or falling on them from a height, as to whether it will break your fall.. I dunno but if it doesn't in the game I'm sure it'll be simple enough to add the support in a mod.

It would be cool to have and make for some fun MP games along with the above and previously mentioned using the objects on the map as traps and weapons

 

[alehm]

[headcrab]This was already posted in June 16, 2002 at 2:19pm CST n00b[/headcrab]


hehehe... just kiddin'. I am wondering the same thing myself.

 

[Kwyjiboman]

I can just imagine the fun i'll have of taking jumpts and falling on some combines with the buggy and look at them splat on the asphalt...hehe:bounce:

 

[zdub]

k, ima try and explain this.

its been stated that some objects physics will be server based. (doors for example) so that if one player opens it, it will be open for the next player that comes around

on the flipside however, smaller and less important objects that still have physics applied to them (cans, garbage, old tires? etc) they have client based code...meaning if you shot a can, you could see it go in an entirly different direction then a player beside you.

this is done because plain and simple the server wouldnt be able to make all those calculations for cans, large objects etc, just not possible at this point.

soo your question is interesting in that, only certain objects designated by the server that have physics applied to them will be able to hurt you if they go flying into you for example....cause if its client side...well it would be easy to hack for one. and for two how would the server be able to guess that the stack of bricks that you blew up next to another player did damage to him and how much,,,keeping in mind its client based.
make sence?

 

[poseyjmac]

zdub, so if things like tires are client based, then if i get the gravity gun and propel the tire at someone it means nothing. that can't be how they handle it, because thats one of the gameplay features they boast about.

 

[Chris D]

This is what Apos posted in the Valve info thread a few months ago:

"from: Timm

The physics in the single player part (judging from the movies from E3) look absolutely fantastic, but how will physics work in multiplayer? Won't there be a problem with sending all the physics information packets to all the players? Are you perhaps scaling the physics engine down for multiplayer?

Gabe
"Well, the simple answer is that there are client-side and server-side physics behaviors. You use client-side when maintaining cross-client coherence isn't important. This cuts down network traffice while maintaining the appearance of physical simulation throughout the world.

Yahn, anything you'd elaborate on?"

Yahn (follow up on Gabe's question)
"No, that's basically correct."

Me (asking for clarification)
"So basically what you are saying is that the physics appear to the player just like they do in the single player game without scaling it down, but objects that aren't required to have a correct placement in the world (like soda cans, small rocks, and so on) will be handled client-side, but bigger things (like a crate that's thrown on a player with the gravity gun, or a mattress falling down to block a hole in the ground) will appear in the correct spot for all players?"

Yahn:
"Yes, it's definable per-object, so exactly what's client vs. server simulated is tunable.""

 

[Chris D]

So from that, what I'd assume is that all the little things like cans, bottles etc. that won't cause damage will be on the client side. At the end of the day, their position in the world doesn't affect the other players at all so it doesn't have to be spot on in the right place.

However bigger things; tyres, crates, matresses, boxes, radiators that would cause damage to a player will be done client side. The items need to be spot on. If you shoot a crate at someone and it's all processed client side, basically for one client it'll hit another player, and for another it'll miss. However, if those are prossesed server side, if it hits someone, everyone else will see it hit someone.

Basically, anything that needs to happen exactly the same for everyone will do so server side; otherwise the client can handle it.

 

[The Dark Elf]

That'll be handy, if used correctly eg: not forgotton about by the mod makers. It should mean online games in HL2 can be pretty speedy and still look good and behave correctly

 

[poseyjmac]

so im assuming its definable in the map making process only. itd be nice if there was also a server command, that way if you play the same map on lans, you can afford more server based physics

 

[Netherscourge]

Hmm - I guess I understand now.

So I guess something like pushing a large dumpster (like the one in traptown) on top of another player in a multiplayer game, would kill them real good?

Also - can someone be INSIDE the dumpster and then pushed off the side of a roof?? You know, like WWE style! lol

If so, I'mm gonna hide in dumpsters and jump out and shoot people as the run by - unless someone tosses a grenade into it.

 

[poseyjmac]

yes nether. you can literally be inside a whole house and have it fall under the effects of physics, and you will die too.

 

[Chode]

Yep. If a character has a large force suddenly applied to them, they die.

In the most recent interview I read, it was said that originally they had never thought of running soldiers over using the buggy. They'd just made the physics buggy, made the soldiers, everything physicsed (is that a word?), and they thought that players would get out and fight the soldiers with a shotgun or something. Then one of their play testers ran them over instead. If I remember exactly, the first thing they said to this was "we need a sound effect for that".

Also, it has been said that the zombies will now try to throw stuff at you. In the e3 movie, it can be seen that a zombie will kick a barrel at you. I'm assuming that if it contacted, it would cause some damage, otherwise the whole codepath of objects been thrown at you would be a massive waste of code.

 

[Chris D]

Chode, in the E3_traptown video, the barrel does actually hit Gordon and does actually inflict damage.

I think it looks pretty cool.
And that contextual AI thing sounds pretty cool too.

EDIT: Oohh... I lied... It doesn't hit him. Hadn't watched it for a while

 

[Washuu]

Washuu --[box]-- > Nub1123


hehhe, id love to see that, washuu kills some with box

 

[Chode]

Originally posted by Washuu
Washuu --[box]-- > Nub1123


hehhe, id love to see that, washuu kills some with box

Be cool but I think instead it would use something like "Washuu killed Nub1123 with world object" or "Washuu killed Nub1123 with Physics object".

Wonder if you can kill someone with a dead body. Hit em hard enough and would they do....or would the corpse disentegrate....hmmm

 

[Non-Sequitur]

So the question is: how many large objects like crates and barrels will a multiplayer map be limited to?

 

[poseyjmac]

there will be no limit, its up to the map maker. you can be sure there will be many maps that will be chunky as hell to play with 1000s of physics objects. so people will need to learn that even the source engine has limits.

 

[Korgoth]

i would love to see the physics in multiplay, but something is definately odd, i remember reading stuff on ut2k3 when it came out, the physics calculation for ragdolls alone would cause so much lag that they had to rework it to where the ragdoll the dead player sees of themselves is calculated where as the ragdoll death the killer sees is different all together so i wonder if valves code will allow for that much physic interaction in mp without compromising gameplay

 

[Non-Sequitur]

Well, I guess it's not really the Source that sets the limit... it's the hardware you're using to play the game. Lets hope too much in the way of physics objects doesn't cause server crashes.

 

[zdub]

Originally posted by poseyjmac
zdub, so if things like tires are client based, then if i get the gravity gun and propel the tire at someone it means nothing. that can't be how they handle it, because thats one of the gameplay features they boast about.

read chris's post.
see

 

[poseyjmac]

see what? no one is going to make things like tires client-based. or else itd be like shooting blanks at people, you would see people running around thinking they have something with their gravity gun. is it possible, yes, but a map maker would have to be an idiot to let that happen. thats why you WONT see objects that have enough weight to hurt someone client-based.

 

[UDHA]

the client-server based physics means major things that will have an impact, say a car, will be done from the server, but say you kill somebody, their ragdoll animation is going to be processed differently on each computer playing, although with the same velocity from the impact I hope. We don't know exactly what will be done how, that is something they want to keep secret until it is released.

 

[Korgoth]

i dunno it would be amazing to me if they could/did pull it off, and even though they are being very secretive about the multiplayer component to half life 2 they have boasted as to how improved the netcode is so i guess its another one of those wait and see situations... My only fear is that they couldn't incorporate the physics, could you image the strain that all these physics calculations would put on both client/server... imagine this:

Your in a map with say 32 players, you have a phys gun and pick up a car thats in the middle of the map you lift the car, and everyone else's computer has to be told that you lifted the car and your holding the car, then say "bob" picks up a barrel, everyones machine is told this info as well, then "steve" kills "bob" with a crate that breaks and splinters, now they could get away without telling everyone the crate splintered, but everyone would have to recieve the crate drop/barrel drop and you still holding the car info etc etc. I just can't imagine how they could handle these loads and still keep they gameplay smooth and believable..

 

[JohnnieWalker]

can we see the ragdoll physics in hl2? that would be really cool i love this ragdoll stuff in max payne 2...

 

[just a headcrab]

Could they not implement full physics for multiplayer if it was for LAN mode? At least as an option for LAN games, seeing as network traffic isnt so much of an issue where we're talking considerably faster connections, all within a local area network.

 

[The Dark Elf]

Originally posted by just a headcrab
Could they not implement full physics for multiplayer if it was for LAN mode? At least as an option for LAN games, seeing as network traffic isnt so much of an issue where we're talking considerably faster connections, all within a local area network.

There really wouldn't be much need, UDHA has the right idea. The important things that actually will have an effect on gameplay will be server side, so everyone see's and experiences the same thing. But smaller stuff like cans from vending machine, or the shards of wood from blown up wooden objects things like that will be client side as it wont make any difference really what they look like between two different machines. In practice its very unlikely anyone will notice any difference visually, unless you sit and watch something happen looking at the same event from two machines at once. Actually playing normally it wont make a difference other than it'll be faster games, even across LAN it'll be faster that way.. But of course there wouldn't be anything stopping someone making mods where its all done server side, but people are bound to complain about that I bet, especially if they keep getting killed a lot, isntead of the old excuse of "im lagging stop it!" it'll be "yeah well the map maker made all the physics server side and its screwing things up for me" heh

 

[Mechagodzilla]

On a related note: If you jumped off a building and landed on a pile of mattresses, would you take less damage?

 

[Sparta]

I'd say the ragdolls are better, HL2 uses friction with the ragdolls, unlike Max Payne 2