[James Ross]

rdamurphy, on 18 January 2014 - 03:33 PM, said:

Glad to hear that! I worked on that for quite a while and couldn't get it to work. I'll have to take a look at that and see how you accomplished it...

BTW, there are a number of VERY much better smoke textures available for MSTS that could be replaced making OR smoke look much better as well...

I had to do some integration for the first time in about a decade. ;) The two values that'll need tuning are XNAInitialVelocity (based on the emitter direction and emission rate) and XNATargetVelocity (fixed at 1m/s upwards right now).

I need to figure out what kind of texture we need (greyscale, alpha blended, etc.) to achieve the desired results, then see what people can turn up that we can use. :)

[susquehanna]

,first one idling,second full throttle ;)

[PA1930]

Haha! :) And I was the one saying to my friend that his train looked like he had a smoke fountain on our multiplayer session... :jawdrop2:

http://i40.tinypic.com/2rdhlxg.png

Although I didn't really take many screenshots of my own train, the smoke effect had already some tweaks on it so the smoke didn't look as extreme as any of these previous trains... So now its either a question of everyone adjusting the loco's smoke effects, or just some more further adjustments on ORTS's smoke effects. ;)

[gpz]

Just a note: CrisGer offered his high quality steam smoke texture for inclusion into OpenRails.

[James Ross]

What I really need right now is not a new texture (although that's appreciated) but some hard data. :( I'm sure there are people with some data on this so, for a single steam locomotive:

• What is the smoke stack diameter?
  
• What is the typical volume of exhaust coming out of the smoke stack?
  
• What's the curve of smoke like when operating? (Pictures appreciated.)

The problem I've got is that the inputs to the emitter code have been tuned for the old behaviours, but since all the inputs are data (sizes, volumes, etc.) I want the emitter to be as close to reality as possible - and then have the MSTSLocomotive code be tuned to correct for any weirdness that produces due to MSTS data.

E.g. the MSTS in-box Flying Scotsman locomotive has a smoke stack area of 0.031416m^2 and in current OR full-throttle emissions of 12.322m^3/s. That's 392m/s = 1411kph. That seems a bit fast to me.

[markus_GE]

Genma Saotome, on 18 January 2014 - 02:51 PM, said:

WRT the graphics tho... those circles of exhaust. I know that was just an example...

The circles in my description are really just examples, but from what I´ve seen, OpR currently uses something very similar to these circles. I´d call it patch (though the proper term would rather be particle, I think). Anyway, if these are displayed close enough to each other, overlaying another, the outlines will disappear, thus making for a plume. At least, as far as I can imagine :(

Cheers, Markus

[RTP]

I tried x1947 with an UP9000 and the result is, say, ridiculous.
In my opinion must be:
A kind of "efluves" generator, controled for many parameters.
For instance, position, direction, size. The size of the security valve of a small loco is, say, 20 square centimeters. The size of the resistor box of a big electric is two square meters.
Kind of efluve, steam, white, or smoke, from ligth brown to very black. Some controling curve.
Initial speed.
Conditions. A resistor box steams under rain or snow, and braking.
Triggers. Security open, horn.
Syncs. With the main wheels.
Persistence. Steam dissolves in the air. Smoke does not.
Flow. Big for a Big Boy. Small for an electric braking.
And many more.

Regards.

[Matej Pacha]

James Ross, on 19 January 2014 - 04:00 AM, said:

What I really need right now is not a new texture (although that's appreciated) but some hard data. :( I'm sure there are people with some data on this so, for a single steam locomotive:

• What is the smoke stack diameter?
  
• What is the typical volume of exhaust coming out of the smoke stack?
  
• What's the curve of smoke like when operating? (Pictures appreciated.)

The problem I've got is that the inputs to the emitter code have been tuned for the old behaviours, but since all the inputs are data (sizes, volumes, etc.) I want the emitter to be as close to reality as possible - and then have the MSTSLocomotive code be tuned to correct for any weirdness that produces due to MSTS data.

E.g. the MSTS in-box Flying Scotsman locomotive has a smoke stack area of 0.031416m^2 and in current OR full-throttle emissions of 12.322m^3/s. That's 392m/s = 1411kph. That seems a bit fast to me.

James, I'd like to give you a hint here on the smoke curve. I suppose the speed could be an decreasing exponential shape (easy to code), the initial speed is the same as the train speed in two directions (x,y) and it should approach the wind speed (some small value could be set for this). The third component (z) should depend on the smoke production (throttle). We can also set different dynamics for a steam smoke and a diesel smoke, since they have different density and weight. I'll be able to have a look at it next week. Where is the smoke movement computation code?

[James Ross]

Matej Pacha, on 19 January 2014 - 06:04 AM, said:

James, I'd like to give you a hint here on the smoke curve. I suppose the speed could be an decreasing exponential shape (easy to code), the initial speed is the same as the train speed in two directions (x,y) and it should approach the wind speed (some small value could be set for this). The third component (z) should depend on the smoke production (throttle). We can also set different dynamics for a steam smoke and a diesel smoke, since they have different density and weight. I'll be able to have a look at it next week. Where is the smoke movement computation code?

Seriously, this is all stuff that I know (some of which is in the model and some which will be), but doesn't answer any of my questions.

[James Ross]

In X1949, I added the velocity of the stack to the initial particle speed (in addition to the already-added emission velocity).



Getting there, I'd say. Still need some real data to work out when the emitter inputs are bogus though.