[_o_OOOO_oo-Kanawha]

Yes, me too thinks this is coming along nicely. Is there any real visible difference between the various smokemain.aces in ORTS?

Does AI's smokestacks behave the same by default?

I think it is best to have active steam engines always have some exhaust, wether throttle is open or not. A completely clean stack doesn't look right to me.

Or one should add a small whisp of steam here and there, like at the pop valves, live steam injector, turbogenerator or compressor exhaust to indicate the engine is 'live'?

In RailWorks I always add small steam emitters at above locations and try to link them to the cab controls, also the stoker engine, so they come on and off when the appliance is actuated either manually or by the auto-fireman.

[Genma Saotome]

Is possible to tweek the emitters & color to the individual locomotive (via instructions, say... embedded in the .sd file)?

[markus_GE]

AFAIK (and that´s from Diesel exhaust) Emitter positions can be tweaked from the .egn file. About Color, there´s no Options for diesel, and I guess that´s the same for Steamers. HAving look into the .eng of the Default Gölsdorf 380, those assumptions can be confirmed.

Yours, Markus

[James Ross]

Walter Conklin, on 26 September 2013 - 11:27 AM, said:

Hello,

I understand that the smoke and steam effects in OR are a work-in-progress. Just curious - What would it take to get the steam locomotive smoke in OR to appear at times like the smoke shown below?

I think we'd need more behaviour in the particles; at the moment they have a pretty straight path with linear expansion and rotation IIRC.

[Genma Saotome]

Something I noticed in the photo Walter posted... the exhaust goes pretty much straight up for about 16 feet (the height of the locomotive), begins to bend a tiny bit for maybe another 4 or 5 feet, and only then begins to bloom and be carried away.

Makes me wonder about the relationships between the force that moves the exhaust, the speed of the locomotive, and the speed and direction of the wind.

Consider with any steam locomotive, standing still with no measurable wind, we should see the exhaust go straight up. Change that to having wind a x speed moving at right angles to the locomotive (still not moving) and we might see the plume of exhaust moving in some manner in the direction the wind is blowing. Once the locomotive starts to move we have two directional forces at play -- the wind from the right angle and the speed of the locomotive... two forces, perhaps in a simple ratio to each other (e.g., if locomotive and wind speeds are identical but at right angles to each other, the plume of exhaust might move at a 45d angle away from the direction of both forces).

Second thought is WRT to the height of the exhaust plume. Obviously an exhaust force that is greater will throw the exhaust higher into the air than one that is less. Do we have any data for this force? If we do, what ratio is seen between that force, some reasonable "runoff" thru distance, and the locomotive moving forward in still air? IOW is there a reasonable way to calculate when the vertical throw of the exhaust will begin to bend and then bloom when the force of locomotive motion exceeds that of the exhaust movement?

[rdamurphy]

The height and direction of the smoke comes directly from the parameters in the .eng file, and are different for every locomotive. It would be impossible to code it to work differently, other than perhaps lowering the smoke plume with speed, which is a possibility.

However, I learned the hard way with the diesel exhaust that trying to change those parameters to make it look good on one locomotive may make it look horrible on others...

Height of the plume does change with throttle and cutoff changes, simulating the upward force, or it should?

Also, OR doesn't simulate wind. If it did, it could be programmed, but as is, there's really nothing that would work because hard coding it would cause weird effects as you changed direction, etc.

Robert

[SD45T-2]

I'm just going to interject here.

There should be a puffing effect.

Smoke is blasted up into the air like a cannon, and that adds a lot to the look of smoke.

So, little puff, big puff, etc...

Stack smoke is never a stream, unless it's a steam turbine.

[CrisGer]

that puffing is accomplished by having cycles in the ACE at least that is the theory. This sort of sim is not easy to simulate complex gaseous particle flows, one of the most challenging things for such sims is realistic smoke... as for the rising up of that photo, that engine was probably not moving that fast at the time for usually if there is speed on the smoke blows back along the train as well as rises at a greater factor than 1:1, esp if there is speed on or wind blowing...what gives the most volume to real smoke is cold weather in which cases there is a lot, due to condensation, I will be happy if we can get close to what MSTS can do with a good ACE. :lol2: over time we can maybe add tweaks and improve behaviour.

[rdamurphy]

James Ross, on 26 September 2013 - 11:32 AM, said:

I think we'd need more behaviour in the particles; at the moment they have a pretty straight path with linear expansion and rotation IIRC.

Agreed. There is some randomness in the particle generator, but not in the direction or size of the particles.

I spent some time watching the MSTS smoke, and it even does flips! I'd love to see what they're doing, but I did notice that the smoke effects repeat - more like an animation, where OR effects are far more random.

Robert

[Buttercup]

The front of a moving locomotive will push and deflect the air in front of it which may "protect" the plume until it rises above the deflected air.