Death physics in HL2...

btw: every part of the body in css has his own weight as far as i remember
AND
the movement when dying affects the ragdoll ! when someone is shot in the leg while he is strafing:
-his leg will be pushed back a little
-he will probably fall to the side he strafed to
however, i think the css/hl2 ragdolls are VERY good and DO in fact represent what happens to a body in the real world (when shot)
 
About the one weight thing, that is not true. Diferent limbs have different weights. That's why they fall face forward more often than falling straight backwards. The upper body has the most weight, so it topples forward.
 
thefiznut said:
About the one weight thing, that is not true. Diferent limbs have different weights. That's why they fall face forward more often than falling straight backwards. The upper body has the most weight, so it topples forward.

Oh... I thought that was from us shooting folks in the back more often than not. :E
 
Biozeminade said:
It could if you had armor on, right?

I imagine if the round was sufficiently heavy enough, maybe a close range shotgun blast or a high caliber round, it would likely have enough force to knock you over(well off balance atleast).

I've heard it's like being hit really hard but I've never been(and hope never will be) shot at by a gun toting loony (nor have I got any kevlar!) to actually know for sure:)
But if it is like being punched (low caliber=mr burns(maybe smithers) high caliber high velocity round=mike tyson:D )then I'm sure it depends how good your balance is, what position, or transition your body is in(or going thru), where you are shot, where you are shot from etc.....dead easy to work out I'm sure

(not by me, my brain turned to cheese years ago, I had to ask malcolm, the mouse who lives in the space between my ears, for the answer to this question. I can only hope he's right, but he has a habit of telling me to say the wrong thing, so I make a tit of myself)



;(
 
As far as bullets knocking you over - the only energy that's important in the bullet is the kinetic energy it has, or the amount of energy that's keeping it moving.

When you fire a gun, you feel a kickback as the bullet flies forward. That's because of the ever-popular Newtonian postulate that every action has an equal and opposite reaction. This means that the amount of energy put into the bullet to send it forward is the exact same amount as the energy going back into the gun, causing kickback.

So now your bullet is moving along, let's say with 100 Speed. The bullet has a certain mass, let's say 1 mass. When it hits a person, assuming a complete transfer of energy, the bullet's energy goes to zero. This energy has to go somewhere - into the body of the person being shot. Kinetic energy is conserved (this is an ideal situation, in real life you'd probably just use a conservation of momentum, but hey). Kinetic energy is defined as one half of the product of the object's mass times its velocity squared. (1/2*m*v^2) Let's say your target weighs 100 mass, and wasn't moving when he was hit. The kinetic energy of the bullet would be 1/2*(1 mass)*(100 Speed)*(100 Speed) = 5000 Energy. Now the kinetic energy of the target would be 5000 Energy, which would equal 1/2*(100 mass)*(x Speed)*(x Speed). This turns into

5000 = 50*x^2
100=x^2
10=x

So the speed of the body is a lot lower than the bullet.

Now this would either be a VERY big bullet (we're talking tank shells or something - which would travel through someone)

Or you could do it the easy way and realize conservation of energy means the push on the target can't be any worse than the recoil of firing the gun in the first place. :p
 
The only times I see ridiculous poses in CS:S is when a grenade mangles a body. :) Otherwise they usually look very realistic in their poses. Valve did a great job on it.
 
env_explosion said:
Really nice videos. You're a natural scientist. :D

Funny you should say that........i'm going to be one! (god that sounds weird :/)
 
Maui said:
As far as bullets knocking you over - the only energy that's important in the bullet is the kinetic energy it has, or the amount of energy that's keeping it moving.

When you fire a gun, you feel a kickback as the bullet flies forward. That's because of the ever-popular Newtonian postulate that every action has an equal and opposite reaction. This means that the amount of energy put into the bullet to send it forward is the exact same amount as the energy going back into the gun, causing kickback.

So now your bullet is moving along, let's say with 100 Speed. The bullet has a certain mass, let's say 1 mass. When it hits a person, assuming a complete transfer of energy, the bullet's energy goes to zero. This energy has to go somewhere - into the body of the person being shot. Kinetic energy is conserved (this is an ideal situation, in real life you'd probably just use a conservation of momentum, but hey). Kinetic energy is defined as one half of the product of the object's mass times its velocity squared. (1/2*m*v^2) Let's say your target weighs 100 mass, and wasn't moving when he was hit. The kinetic energy of the bullet would be 1/2*(1 mass)*(100 Speed)*(100 Speed) = 5000 Energy. Now the kinetic energy of the target would be 5000 Energy, which would equal 1/2*(100 mass)*(x Speed)*(x Speed). This turns into

5000 = 50*x^2
100=x^2
10=x

So the speed of the body is a lot lower than the bullet.

Now this would either be a VERY big bullet (we're talking tank shells or something - which would travel through someone)

Or you could do it the easy way and realize conservation of energy means the push on the target can't be any worse than the recoil of firing the gun in the first place. :p


What he said:)

(on a side note kick back from some guns is quite hefty, I've fired a 3.03 and 2.02 rifles and if you don't push your shoulder into the butt of the gun, it doesn't arf crack your shoulder when you fire
- my mate(well he was with us and I knew him but he was a tit:D) said he had a dead arm after the first 2 bullets he fired. I learned after the first one to grip a bit tighter:) (P.S. my "mate" was a pussy aswell- instructor should have tought him how to look down the wrong end of the gun when he fired pffft :sniper:
 
Ruuustar said:
Maybe ragdoll isn't the way to go...
There is a technique that can blend keyframe animation and "ragdolls" for more interesting death animations. There was a company that did some work in this area and boldy proclaimed that "Ragdoll is dead!" though I don't remember who it was.

That said, ragdolls serve their purpose of eliminating repetitive canned animation and reducing clipping to a significant degree.
 
Drayvn said:
in reality the shockwave will probably not kill u unless ur directly on top of it or right next to it, its the fragmentation of the metal casing that kills u and so if u die from a grenade u will also crumple as the shockwave will pass right before the fragmentations hit u as its faster.
Actually, the main cause of death in a grenade explosion is the concussion which is powerful enough to seriously damage internal organs.
 
(oops this has basically been said above)

A bullet hitting your body is a simple conservation of momentum problem. Basically the bullet will 'push' you just as hard as it 'pushed' the shooter. Armor makes absolutely no difference to the amount you get 'pushed'. All this hollywood stuff about people getting blown back is bullshit.


BTW Maui, you use of energy is incorrect.

"This means that the amount of energy put into the bullet to send it forward is the exact same amount as the energy going back into the gun, causing kickback."

The energy in the bullet is much MORE than the energy put into the gun. The MOMENTUM is the same, not the energy.
 
wayne white said:
i bet that ragdolls in hl2 looks the same as cs:s...bummer.

I myself dont think so, i suppose it will have to cut some of it out to save bandwidth and not put to much detail in ragdolls, but i still think there will be a fair amount, well more than any other MP game.
 
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