How far is physics implimented? (Physics

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staddydaddy

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I was just thinking how far the physics engine incorporates physics? I was just thinking about throwing objects in game (something we're obviously going to be doing a lot of). And with throwing objects one has to use conservation of momentum. For those who haven't studied physics, or didn't pay attension:

momentum = Mass*Velocity and conservation of momentum states Mass(1)*Velocity(1)= -Mass(2)*Velocity(2).

Therefore if we say threw an object of mass 20kg with a velocity of 9 M/S perpendicular to the normal the reactive momentum of the player would have to be 180 kg*m/s. Let's say that the mass of the player was 90kg (200lbs)And through algebra the thrower would have a velocity of 2 M/s backwards. At this point the player would have a KE of 180 joules. (1/2*mass*velocity^2). And would eventually come to a complete stop due to friction. Let's say that the Coefficient of friction between the object was .5.
Work = Force*Distance
Work = 180
Force = mass*g*coefficient of friction
Substitution:
180= 90*9.81*.5*Distance
Distance = 4/9.81 meters

It really doesn't seem like in the vids that Gordon shoots back half a meter when he shoot relatively heavy stuff with the manipulator.


and I just realized this was a really dorky thread
 
uh...i'm sure tha it's all implemented on source every bit of it, the physics rules and stuff...right......
 
Source has been in the works for more than 5 years, the physics are as realistic as Valve will ever want them to be.
 
Six Three said:
its a frigging GAME!
Click to expand...

yeah a "frigging game" with a supposedly very good physics system. I'm wondering how good it is. Just like how people question the AI, graphics, and now physics.
 
MC=2....or wait?

Uhh btw this is way too heavy for me...you should'nt look into to this stuff in an academic way, you'll just end up confused and raped.
 
well, i'm sure the physics would be much more realistic but valve probably thought it wouldn't enhnance the gameplay as much as if they just made the physics are arcade like
 
It's F=m*a as far as I'm aware, so not velocity but acceleration.

But physics are being taken that far in the game, and it follows the Newtonian law of every action has a reaction.
The reason you don't see Gordon flying back is because the manipulator seems to make objects massless, so the force applied on the object, and thus on Gordon, only needs to be very small and is too small to set Gordon in motion.

But ffs, IT'S A GAME! :p
(only reason I'm replying to this because I have finals in phyics on tuesday)
 
liquids wont be physically simulated IIRC
 
maybe the manipulator compensates.. but .. WHO THE FUDGE CARES! dear god in heaven :O
 
staddydaddy said:
I was just thinking how far the physics engine incorporates physics? I was just thinking about throwing objects in game (something we're obviously going to be doing a lot of). And with throwing objects one has to use conservation of momentum. For those who haven't studied physics, or didn't pay attension:

momentum = Mass*Velocity and conservation of momentum states Mass(1)*Velocity(1)= -Mass(2)*Velocity(2).

Therefore if we say threw an object of mass 20kg with a velocity of 9 M/S perpendicular to the normal the reactive momentum of the player would have to be 180 kg*m/s. Let's say that the mass of the player was 90kg (200lbs)And through algebra the thrower would have a velocity of 2 M/s backwards. At this point the player would have a KE of 180 joules. (1/2*mass*velocity^2). And would eventually come to a complete stop due to friction. Let's say that the Coefficient of friction between the object was .5.
Work = Force*Distance
Work = 180
Force = mass*g*coefficient of friction
Substitution:
180= 90*9.81*.5*Distance
Distance = 4/9.81 meters

It really doesn't seem like in the vids that Gordon shoots back half a meter when he shoot relatively heavy stuff with the manipulator.


and I just realized this was a really dorky thread
Click to expand...
WTF.....???
 
It really doesn't seem like in the vids that Gordon shoots back half a meter when he shoot relatively heavy stuff with the manipulator.
Click to expand...
If you can manipulate gravity, I'm assuming there's some antimatter shield or something that stops kickback, or whatever it's called. I mean really, the manipulator would have to bend gravity.

I wonder if you can throw people? What would it do to a person that way?
 
i think its called zero point energy or something
 
really your question is completely irrelevant (no offense ;). basically you're wondering if gordon is pushed back after shooting a heavy object with the manipulator gun. this makes no sense because the manipulator gun is obviously not real. you can't just suck up some object and suspend it in mid-air and then be able to shoot it away with super force. obviously there is some rediculous (fake) technology there, which could very include the ability to counter the "push back" from shooting something.
 
You can't start slagging this guy off, just because you don't know what he's talking about!

But yea, the manipulator uses 'zero point energy', so I'd be confident that 'conventional' rules such as conservation of momentum are thrown out the window (pun semi-intended).
 
if you want to analyze Hl2 for realism then you have to say this to yourself...


Aliens
Ruined earth
massive biomechanical striders
flying manitees
portals
a guy in a mechanized suit
gigantic building eating a city.....

Physics would not be the first thing i would question in regards to realism.
 
PvtRyan said:
It's F=m*a as far as I'm aware, so not velocity but acceleration.
Click to expand...

That's one of newton's law but it doesn't apply to this situation. f=ma applies to when a constant force is being applied to a mass, which is not occuring in this situation.
 
but the gun does recoil indicating that the momentum is being dissapated the force produced is not moving gordon becasue his fmax friction is greater than the force being enacted on him.
 
Dougy said:
if you want to analyze Hl2 for realism then you have to say this to yourself...


Aliens
Ruined earth
massive biomechanical striders
flying manitees
portals
a guy in a mechanized suit
gigantic building eating a city.....

Physics would not be the first thing i would question in regards to realism.
Click to expand...


Haven't you ever been to Hungary?
 
I dont think they will implement physics to the point where it will degrade gameplay (Having gordon get knocked back when he shoots the manipulator)
 
Actually I think this is a worthy topic, it's good to see that other people with knowledge of physics are analysing it. However I think you forgot to take friction into consideration, seeing as Gordon is wearing a HEV suit, which is designed to protect the user from hazards (as well as enhance strength) it seems likely that the suit would counteract the force with friction and the enhanced strength, I also think it's safe to assume that the suit has some of way to dissipate impacts (which would absorb the force) to avoid damage on the user.
 
Cylleruion2012 said:
Source has been in the works for more than 5 years, the physics are as realistic as Valve will ever want them to be.
Click to expand...

i dont think this is true, source has prolly been in the works for 1.5-2 years...


you know valve, they have probibly started half-life2 over like 3 or 4 times, went between 3 differant engines, ect... over the years
 
I believe the Havok engine conserves momentum, which it automatically does in the case of a collision. Since with the manipulator there is no collision (and because it would make gameplay annoying), they implemented shooting an object by simply eliminating the forces that hold the object in the air and setting its velocity to some constant magnitude in the direction its aimed in.

As far as a real-life explanation, let's pretend like the "zero-point" effect really works. The zero-point is the point at which all forces cancel, and the object doesn't want to move. In fact, an object by the zero-point will be drawn towards it until all forces cancel. So "on the ground" would be a trivial example of a zero-point. The manipulator can just make a zero-point somehow (doesn't really matter how, since it's just a game). It just quickly moves that zero-point away from itself, the object follows the zero-point and accelerates, then is released.
 
Actually, I don't think of Valve as a collection of engine hoppers myself... I suspect that any "previous" engine attempts would be merged, considering they've made Half-Life 2 effectively from scratch ('cept for that specially commisioned customised Havok).

I think the biggest point here is gameplay > realism. Everyone keeps saying it, but if realism is taken to such an extent that it becomes detrimental to the average players enjoyment of the game, I don't think we'd see it. So as great as it would be for fully (that is, completely-true-to-life) physics, we won't be seeing 'em...
 
I think you have to consider this in the context of what we already know about the gun. it makes heavy objects hover, this means reducing the effect of gravity, gravity is believed to be a very long wavelength form of electromagnetic radiation so theoretically it could be blocked. or alternatively new gravity waves could be formed to suspend the object, I found on t'nternet a thing about the hutchinsons effect (it actually mentions zero point energy!) : hutchinsons effect

"The Hutchison Effect occurs as the result of radio wave
interferences in a zone of spatial volume encompassed by high
voltage sources, usually a Van de Graff generator, and two or
more Tesla coils.
The effects produced include levitation of heavy objects,
fusion of dissimilar materials such as metal and wood...etc"

so - what we would need is a large van der graff generator or a tesla coil (these are not actually very similar to the red alert stereotype(if that is the right word)). Both need a good power supply and are noisy - (a tesla coil makes a similar noise to that made by the manipulator in hl2) luckily gordon has his HEV to powers the suit which probably has the added avantage of providing a faraday cage like protection from the static charges that would no doubt build up on the manipulator - maybe the latent charge could be used like a taser?

how to explain the orange light: the technology is a prototype so it is probably fairly inefficient in terms of the purity of gravity waves it produces, so it could be releasing some light as well as gravity waves.

I dont know how you would go about constructing gravity waves but I suppose interference of radiowaves might generate a pattern with an unusual wavelength. One possible problem is that gravity waves are weak waves and are only effective with large numbers, they also act over large distances, unlike electomagnetic forces, so the manipulator should be weak and able to pick stuff up from miles away.

but Dr Kliner has probably fixed this problem by concentration of the hutchinsons effect. the three prongs on the manipulator that open likely concentrate the effect, working as arials. However he never did solve the resonance cascade "problem"...

I think it is also interesting to note that in the context of science fiction (for this is the realm we are in) very few stories have the capacity to explain the physics of the science. for example in star trek there are "inertial dampeners" these stop the crew from being thrown into their seats every time the warp drive is activated, (if a person is accelerated at a maximum tolerance G force they would be unlikely to reach light speed within their lifetime!). similarly superman and Star Wars have similar scientific "issues"

There are a number of hypothesis that have not yet been aired over the unacceptably anomalous behaviour of your interpretation of the display of a series of shapes derived from an anonamously pre recorded store of electronic patterns composed in the interests of pure unadulterated entertainment but frankly on this basis it is not really that relavent to the purpose of the images :)

but to pick up on an earlier point - WTF! its only a game :E

AAAAAHHHHHHH! much better :rolling:

I dont get to talk absolute b******cks very often so forgive me

p.s. bit about fusion is interesting/coincidence, no?


edit: change to webpage - fixed link
 
staddydaddy said:
I was just thinking how far the physics engine incorporates physics? I was just thinking about throwing objects in game (something we're obviously going to be doing a lot of). And with throwing objects one has to use conservation of momentum. For those who haven't studied physics, or didn't pay attension:

momentum = Mass*Velocity and conservation of momentum states Mass(1)*Velocity(1)= -Mass(2)*Velocity(2).

Therefore if we say threw an object of mass 20kg with a velocity of 9 M/S perpendicular to the normal the reactive momentum of the player would have to be 180 kg*m/s. Let's say that the mass of the player was 90kg (200lbs)And through algebra the thrower would have a velocity of 2 M/s backwards. At this point the player would have a KE of 180 joules. (1/2*mass*velocity^2). And would eventually come to a complete stop due to friction. Let's say that the Coefficient of friction between the object was .5.
Work = Force*Distance
Work = 180
Force = mass*g*coefficient of friction
Substitution:
180= 90*9.81*.5*Distance
Distance = 4/9.81 meters

It really doesn't seem like in the vids that Gordon shoots back half a meter when he shoot relatively heavy stuff with the manipulator.


and I just realized this was a really dorky thread
Click to expand...

What don't you understand? It's not gordon that's throwing the objects. It's the manipulator! There is no kick back because that's what the manipulator does. It probably just transfers it into some other kind of energy or something. Maybe that's why theres a weight limit too. The heavier, the more energy is required. Why do you think gordon uses the manipulator in the first place instead of just throwing stuff with his arms? DUH! because the manipulator requires no kick backs or work.
 
The Manipulator doesn't have a recoil, you don't force the item off from the base you're standing on, you send it there as if it was gravity or magnetism that pulled it. Gordon doesn't react to anything he's holding (Look at the, what are they called, in the zombie vid where he beats the half-chopped of body in the trees, the thing he pulls up -- Normally that size object would be way to large to hold our your hands and grab, you'd simply fall forward).
 
Qhartb said:
As far as a real-life explanation, let's pretend like the "zero-point" effect really works. The zero-point is the point at which all forces cancel, and the object doesn't want to move. In fact, an object by the zero-point will be drawn towards it until all forces cancel. So "on the ground" would be a trivial example of a zero-point. The manipulator can just make a zero-point somehow (doesn't really matter how, since it's just a game). It just quickly moves that zero-point away from itself, the object follows the zero-point and accelerates, then is released.
Click to expand...

...are you making this up as you go along? I've never heard so much rubbish. :p I think what you *may* be talking about is the point of equilibrium, but it sounds like you're pretty confused about how that works. I've certainly never heard of a physical "zero point". No offence, but I don't think you know what you're talking about... the only point of equilibrium would be somewhere on Gordon's feet, and doesn't really have anything to do with how the gun works.

I think that what zero point energy refers to (and I'd be amazed if nobody's picked up on this before) is the energy present in classical vacuum. The theory goes that it's a property of "quantum foam", the quantum fabric of the universe, where particle-antiparticle pairs are constantly being created and destroyed as result of the Heisenberg uncertainty principle. This produces electromagnetic and gravity waves, and this all contributes to "zero point energy", which is defined as the lowest energy level obtainable, or "ground state". This energy is all around us, but since it's not possible to have less energy, it's very difficult to observe.

Even so, this amount of energy is supposedly huge - I once read that there was enough ZPE in a coffee mug to boil off the worlds' oceans, but don't quote me on that one. The theory is that if we can somehow tap into this, then it could provide a limitless source of free energy, and nobody really knows whether it's possible or not. Personally, I can't see it ever happening, but game developers have all the artistic licence in the world, so who cares?
 
The thing about ZPE, is it's there, but you can't tap it, the particle/antiparticle pairs pop into existence and then destroy each other fast enough so that it doesn't violate conservation of energy. The only time you can directly observe one of these particles is when one of the pair falls into a black hole, and the other escapes. This doesn't violate conservation of energy because the mass of the black hole goes down. This is known as Hawking Radiation.

Physics *never* gives you a free lunch, there's a cost to everything.

Anyways, the logical way I think for the manipulator to work is that somehow it lowers the effective mass of anything it's picked up, for all intents and purposes it is a lot lighter than it was before. Thus, if you apply a force to it, it starts to move really fast, but pushes the quite massive Gordon only a bit backwards.

Of course, then once it's effective mass goes back up once it has left the manipulator, then it violates conservation of momentum. Oh well... it's just a game.
 
the manipulator recoils when fired. Watch the video.
 
Yeh, exactly, the kick-back on the manipulator is the backwards momentum created by launching the other object forwards, but it's pretty small because the effective mass of whatever is being chucked is lowered to well below the mass of Gordon.

Momentum = Mass * Velocity

The mass of the thing is reduced, so it gets a high velocity, but Gordon is still 85kg, pretty damn heavy, so he gets hit with a pretty small velocity backwards.
 
I failed physics and I still understood what the origenal poster was saying with his math. Just a tid-bit of info for you people.

Did you know: That scientist have levitated small animals and insects-arachnids, with large very strong magnetic fields?

I saw the video on the discovery channel myself. They were levitating a spider to study the reaction it would have extreme magnitism. I think the levels of magnitism they subjected the spider to would rip the iron out of our blood but it's still cool to see a floating spider.
 
Strong magnetic fields were the same thing they used in the philadelphia experiment too wasn't it? Though that killed alot of sailors. Heh.

And contrary to what anyone thinks, it really happened.
 
staddydaddy said:
I was just thinking how far the physics engine incorporates physics? I was just thinking about throwing objects in game (something we're obviously going to be doing a lot of). And with throwing objects one has to use conservation of momentum. For those who haven't studied physics, or didn't pay attension:

momentum = Mass*Velocity and conservation of momentum states Mass(1)*Velocity(1)= -Mass(2)*Velocity(2).

Therefore if we say threw an object of mass 20kg with a velocity of 9 M/S perpendicular to the normal the reactive momentum of the player would have to be 180 kg*m/s. Let's say that the mass of the player was 90kg (200lbs)And through algebra the thrower would have a velocity of 2 M/s backwards. At this point the player would have a KE of 180 joules. (1/2*mass*velocity^2). And would eventually come to a complete stop due to friction. Let's say that the Coefficient of friction between the object was .5.
Work = Force*Distance
Work = 180
Force = mass*g*coefficient of friction
Substitution:
180= 90*9.81*.5*Distance
Distance = 4/9.81 meters

It really doesn't seem like in the vids that Gordon shoots back half a meter when he shoot relatively heavy stuff with the manipulator.


and I just realized this was a really dorky thread
Click to expand...

basically u should get a kick-back from the weapon relative to the size of what your throwing just like the amount of kick back your get from a gun is dependant on the power (and mostly therfore the size) of a gun i.e. USP and a shotgun. thats just my way of putting it without inducing a maths related headache
 
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