Can the Source Engine do...

[Mr.Wotsit]

Hey, just a few curiosities I had flying around in my head recently, more tests of the Javok physiscs engine than anything else but here's the list:

Balloons
Can you reverse the directions of the physics within an object? This is the only way I can think of doing it because there isn't really support for physically simulated gases as far as I can see. I suppose the barrels in the puzzle from the canal have some kind of property that lets them lift up to the surface but they are underwater. Perhaps you'd have to implement some of the characteristics of water to the real world?

Trolleys
Now I know there's the baggage trolleys in the train station but their wheels don't move properly. I was just wondering if you could actually implement proper wheels. Perhaps making them properly circular would be the biggest stumbling block.

Anyway, if anyone has any other curiosities, feel free to just stick them in this thread!

 

[PvtRyan]

The thing that makes the barrels float is buoyancy, I suppose this could be applied to air as well if you cover the map in some sort of func_air brush with nodraw textures, or just a brush with a material that gives it certain properties like the water material does.

As for wheels, they're fine in HL2 as they are aren't they? Just give them enough friction and they'll turn like they should. The buggy for example, moves purely because a force is applied to the wheels and the friction with the ground propels it forward.

 

[Deadeh]

i also thought of something and wondered if it could be done this morning, anyway here goes;

would it be possible to pour out petrol onto the ground/object, be able to pour it in any way you like (in a line, pattern whatever) then light it so it all goes up in flames (in whatever pattern you did it in), only use of it i can think of is some sort of trap.

If you dont have a clue what im talking about think of the ending to Die Hard 2

 

[Sucky Ducky]

To Deadeh: I'm pretty sure that should be possible

 

[nagual678]

maybe you can do some sort of liquid trail simulation like there is in Postal 2

 

[dru]

yeah postal 2 had a really nice oilcan, making huge traps and bombs out of unprimed grenades and the oilcan + matches was so much fun

 

[Mr.Wotsit]

You could probably assign some kind of flammable flag to a splodge like that bugbait one. I mean, they must have some properties to be able to tell the Ant Lions where to go.

 

[dru]

well if you think about it, how hard would it be to just code in liquid trail physics yourself like they did for postal2?

 

[Psycho]

Maybe, for balloons, you could give them a negative weight, and maybe then they'll go up instead of down.

 

[gXxshock]

As for wheels, they're fine in HL2 as they are aren't they? Just give them enough friction and they'll turn like they should. The buggy for example, moves purely because a force is applied to the wheels and the friction with the ground propels it forward.

Cars in the real world act in the same way, you only move because of the force of friction. Which brings up another question: do the surfaces in HL2 each have their own coefficient of friction ?

 

[westie]

I had another idea could you make the Source engine do my maths homework it could be working it out while i play HL2 then print it all off. That would be great!!!

 

[Zento]

But then you don't learn anything....:dozey:

 

[Brian Damage]

I'm pretty sure helium ballons would just be a matter of a negative weight value, if that's possible. Either that, or a density less than that of air, if that's the way the engine handles things.

 

[Cypher19]

I wouldn't be surprised if Source's physics model density as part of the buoyancy forces. If that is the case, then you could just have some "water" above the ground with a low density, and make the balloon's density even lower than that.

IF Source let you have a negative mass (NOT WEIGHT) then you'd have to keep in mind that any force would work in the reversed direction (F=ma is vector based, not scalar based!).

 

[jimmyjam]

as for the trolleys, go push around the buggy

speaking of pouring out petrol, the liquids (blood pouring downhill etc) were the only good part in postal 2
I stopped playing that game when I discovered the elephants/marching band
triggering a ring of fire to encircle a marching band > all

 

[Acert93]

Balloons
Can you reverse the directions of the physics within an object? This is the only way I can think of doing it because there isn't really support for physically simulated gases as far as I can see. I suppose the barrels in the puzzle from the canal have some kind of property that lets them lift up to the surface but they are underwater. Perhaps you'd have to implement some of the characteristics of water to the real world?

You could just stick a propeller/engine on the ballon that is always pointed up, or in a small cone. This way it can still sway with outside input and wind if you applied such.

 

[semi-psychotic]

If you gave the balloons a negative mass, it would rise through the air faster and faster until it reached terminal velocity, like it was falling upwards. That wouldn't look right.

As for my own curiosities, I'm wondering how advanced vehicle animations can be. I know that spinning propellors and wheels are no problem, but what about... legs? And how about advanced, multiple weapon systems on vehicles? You Battletech/Mechwarrior-types know where I'm going with this.

 

[zencat]

one thing i found sort of interesting: if you stand on a luggage cart and press forward on the handle or sidebar thing the cart moves even though you are not touching the ground in any way. this doesnt work in real life.

 

[Hyperion2010]

For the baloon you could simply set it to have negative gravity.
Wheels for the trolly are proabably simple, like the wheels for the rolling boxes in Nova Prospekt.

 

[zaerkkahn]

I thought water didn't really exist as a physical object in the Source engine, it was merely an area in which objects that entered were defined to exhibit different properties.

 

[westie]

But then you don't learn anything....:dozey:

Who learns anything in school anyway?

 

[Varsity]

If you gave the balloons a negative mass, it would rise through the air faster and faster until it reached terminal velocity, like it was falling upwards. That wouldn't look right.

Er, have you ever let a helium balloon go?

As for my own curiosities, I'm wondering how advanced vehicle animations can be. I know that spinning propellors and wheels are no problem, but what about... legs? And how about advanced, multiple weapon systems on vehicles? You Battletech/Mechwarrior-types know where I'm going with this.

They made the Strider drivable, remember.

 

[nagual678]

They made the Strider drivable, remember.

that doesn't mean it worked/looked good

 

[azz0r]

i also thought of something and wondered if it could be done this morning, anyway here goes;

would it be possible to pour out petrol onto the ground/object, be able to pour it in any way you like (in a line, pattern whatever) then light it so it all goes up in flames (in whatever pattern you did it in), only use of it i can think of is some sort of trap.

If you dont have a clue what im talking about think of the ending to Die Hard 2

Easily.

 

[cojawfee]

And can you make a working train system? I know we had these before, but they could just be animations. Would it be possible to map out a track, put a rail car on it and push it down the tracks?

 

[ComradeBadger]

Annnnnnd you can't have a negative mass

 

[NetWarriorDan]

Negative mass makes no sence to me. Does a real baloon have mass? It should. All you would do is apply a force on the baloon going up. The force would need to be stronger then gravity (9.8m/s^2) to overcome gravity. In other words it's easy to do.

 

[azz0r]

Someone make one.

 

[NetWarriorDan]

I would but I don't have the game yet.

 

[Locust]

With balloons, you could apply a negative gravity to them. Even now you can make all things in half life 2 float with the command: sv_gravity -1000(or whatever value you wish.

 

[Mr.Wotsit]

Just another little item for the list:

Can the Source engine make a spring? I mean, I'm sure you could make a coil but what are the physics behind a spring and does the Havok physics engine support it?

 

[NetWarriorDan]

With a little programming I think you could.

 

[HunterSeeker]

Just another little item for the list:

Can the Source engine make a spring? I mean, I'm sure you could make a coil but what are the physics behind a spring and does the Havok physics engine support it?

I belive there is an entity called physics_spring.