Adjusting Diesel Exhaust Effects in OR

[rdamurphy]

We've had some questions about adjusting the exhaust effects for OR, so here's a summary of how they work:

Basically, what I did was create a consist with the default Dash9 and GP38, and the SD40-2 from the update, and compared them side by side (running MSTS and OR in windowed modes) and tried to make them look as close as possible throughout the throttle range. OR's exhaust is just slightly shorter in height, but I think looks better.

So, those three are probably the best place to start. Also, since the exhaust on one of them, I forget which one, goes from .05 to 4, small changes can be large, and large changes can be huge. Going from 4 to 5 will make a large difference, but you can tweak by going from 4 to say, even 4.05.

Also, the effects also depend on the locomotive engine idle speed and change increments from being correct, as well as the throttle settings. I tested one locomotive where the six lower notches were very close together, with the last two covering probably 75% of the throttle range.

To summarize, the exhaust effects depend on the following .eng file parameters:

Example from SD40-2 default.

Exhaust1

0.0 4.738 1.485
0 1 0
0.1 - width in meters of exhaust nozzle

DieselSmokeEffectInitialMagnitude( 1.5 )
DieselSmokeEffectMaxMagnitude( 1.5 )
DieselSmokeEffectInitialSmokeRate( 0.7 )
DieselSmokeEffectMaxSmokeRate( 2.8 )

DieselEngineIdleRPM( 318 )
DieselEngineMaxRPM( 904 )

Throttle ( 0 1 0.125 0
NumNotches ( 9
Notch ( 0 0 Dummy )
Notch ( 0.125 0 Dummy )
Notch ( 0.25 0 Dummy )
Notch ( 0.375 0 Dummy )
Notch ( 0.5 0 Dummy )
Notch ( 0.625 0 Dummy )
Notch ( 0.75 0 Dummy )
Notch ( 0.875 0 Dummy )
Notch ( 1 0 Dummy )

I hope that helps!

Robert

[bprice]

Thanks. That does help. It is now easy to see why the Diesels West ES44 is such a polluter.

DieselSmokeEffectInitialMagnitude( 0.5 )
DieselSmokeEffectMaxMagnitude( 10.5 )
DieselSmokeEffectInitialSmokeRate( 1.2 )
DieselSmokeEffectMaxSmokeRate( 14.0 )

DieselEngineIdleRPM( 316 )
DieselEngineMaxRPM( 1050 )

I don't relish modifying a significant amount of my trainset folder but this gives me a place to start.

I wonder if it would be possible to add an option in OR to override these .ENG settings and allow the player to set preferences with a slider like the new daylight intensity settings. Perhaps a color slider could be included too.

Keep up the good work. OR just keeps getting better and better.

Basil

[sidp]

There are other diesels with unusually large numbers that smoke badly in OR. There is an ongoing discussion of this on the Elvas Tower Open Rails Forum: http://www.elvastower.com/forums/ind...-is-the-smoke/ . It looks like the original locos - GP38, Dash9, SD402 have reasonable values.

[seagoon]

Whilst on the subject of diesel exhaust effects, I'm wondering if it is possible for anything to be done about the lack of exhaust smoke when the loco is at maximum throttle but moving very slowly due to the load/incline?

In the vast majority of real-life instances the exhaust plumes billow above the locos as they crawl along at maximum revs, yet that effect seems to be missing in OR.
I'm not suggesting that the exhaust should be black but that there should be much more of a visible effect than a few wisps.

[rdamurphy]

If I understand what you're saying, when a locomotive is running full throttle at 8 mph, the exhaust collects overhead?

With OR, that doesn't happen, exhaust particles have a finite life, however, that is definitely something that has been discussed, basing the exhaust volume and direction based on train speed and wind direction.

Good suggestion, thanks!

Also, a program to fix .eng files en masse is in the works by an Elvas Tower forum member.

Robert

[seagoon]

If I understand what you're saying, when a locomotive is running full throttle at 8 mph, the exhaust collects overhead?....

Yes, Robert...that's it.

Thanks for the response.