[Csantucci]

In my experimentation with activity randomizing I wanted to change color of the diesel exhaust simulating a compressor blowdown, but the color was always black. I checked the code and saw that it foresees different colors depending from the fact that power is increasing, decreasing and so on. But the color was always black. Instead for the steamers the stack color can vary (at least its brightness). So I broke my head in analysing the code to find out where the difference was between the diesel exhaust code and the smoke exhaust code. Even forcing a green exhaust I always saw a black exhaust. At the end I found the problem, which is the combination of the default diesel exhaust texture (dieselsmoke.tga) and the way how exhaust color is handled by the shader, that is ParticleEmitterShader.fx.
The problem is that the diesel exhaust texture (differently from the steam smoke texture) is completely black (transparency apart), that is its RGB components are 0, 0, 0. ParticleEmitterShader.fx computes so the combination of the texture color with the diesel exhaust color correction

	tex.rgb *= In.Color_Age.rgb;

(Color_Age.rgb being the color correction of the diesel exhaust code).
The problem is that if the three color components of tex are equal to 0, multiplying them with any value will get as final result always 0 (black).
So the combined effect of this is in my opinion a bug.

I wouldn't modify the shader, because it is used also for the steam smoke and other particle emissions, so I think that one can only change the other term of the multiplication, that is OR shouldn't use the original dieselsmoke.ace file, but an .ace file specific for OR.
This would probably lead also to changes to the logic governing the change of colors for the diesel exhaust, because once operating it does not provide a satifactorily lookout.

Waiting for comments and also for an opinion by James on how to proceed.

By the way this is a very delicate point, because any exhaust which will generated will cause some people vehemently saying that it was better before. Therefore I'm cautious.

P.S. I see that this is was already discussed in the past, but no change to OR was done. I think it could be time for a change.

[elvasleis]

I use this setting in the engine file.
DieselSmokeEffectInitialMagnitude( 0.1 )
DieselSmokeEffectMaxMagnitude( 1.0 )
DieselSmokeEffectInitialSmokeRate( 0.1 )
DieselSmokeEffectMaxSmokeRate( 1.0 )

The reason is I do not like a lot of diesel smoke.

[dennisat]

 elvasleis, on 22 October 2017 - 09:50 AM, said:

The reason is I do not like a lot of diesel smoke.

Modern diesels, in the UK at least, only produce dark smoke (I wouldn't call it black) when the throttle is rapidly advanced. As soon as the revolutions stabilize, there is just a faint grey heat haze from the exhaust. For old models, which were not as efficient, black is probably the only colour needed.
The diesel engine is unfortunately getting flak for certain emissions but it is still the most efficient mobile converter of the energy in fuel available. Modern container ships have a 55% engine room efficiency (includes all parasitic uses of the fuel energy). If the diesel is banned as a freight mover, transport costs will rise by up to 20% I have read somewhere.

Dennis

[Maximus]

Hello Carlo,

have a look at the video. The color of my exhaust gas changes when I switch on power.

https://youtu.be/LRIvBICkIVg

[R H Steele]

The settings below in the ORTSDieselEngines block, produce black, faint blue, and white smoke (credit goes to Tyler Bundy, for the Exhaust Color and Transient color settings, borrowed from the IC SW1400s we worked on together), the rest of the block comes from reading the OR manual, working with Tyler, my readings of op manuals, descriptions at the end of engine files, thread postings, emails with others interested in the ORTSDieselEngines block, The Diesel Shop web site, Wikipedia, and other sources.

When this block is used (or referenced to by a path) in the eng file in the OpenRails folder the MSTS DieselSmokeEffect lines are not used (AFAIK).

So, question to Carlo - what you are proposing would only affect those relying solely upon the MSTS DieselSmokeEffects parameters - it WOULD NOT affect the exhaust parameters found in the ORTSDieselEngines block?

Comment ( Standard ORTS Diesel Engine for SD40-2 )
Comment ( include ( "..\\..\\Common.Std\\Engines\\Std_Eng_SD40-2.inc" ) )

ORTSDieselEngines ( 1
		Diesel(
 			IdleRPM ( 318 )
			MaxRPM ( 904 )
			StartingRPM ( 255 )
			StartingConfirmRPM ( 318 )
			ChangeUpRPMpS ( 75 )
			ChangeDownRPMpS ( 25 )
			RateOfChangeUpRPMpSS ( 5 )
			RateOfChangeDownRPMpSS ( 1 )
			MaximalPower ( 2237.1kW )
			IdleExhaust ( 1 )
			MaxExhaust ( 3 )
			ExhaustDynamics ( 2 )
			ExhaustDynamicsDown ( 0.5 )
			ExhaustColor ( 206B787D )
			ExhaustTransientColor ( 40212324 )
			DieselPowerTab (
  				0	0
				318	0
				393	279638
				468	559275
				543	838913
				618	1118550
				693	1398188
				768	1677825
				843	1957463
				904  2237100
			)
			DieselConsumptionTab (
				0   	0
				318	5.2
				904	164
			)
			ThrottleRPMTab (
				0   318
				12.5   393
				25  468
				37.5  543
				50  618
				62.5  693
				75  768
				87.5  843
				100 904
			)
			DieselTorqueTab (
				0   	0
				318	51155
				904	409236
			)
			MinOilPressure ( 16 )
			MaxOilPressure ( 50 )
			MaxTemperature ( 120 )
			Cooling ( 3 )
			TempTimeConstant ( 720 )
			OptTemperature ( 71 )
			IdleTemperature ( 55 )
		)
	)

[espee]

You can always change the dieselsmoke.ace texture found in the Global Texture folder :) many are and have been available :)

[ErickC]

We should probably create a default smoke texture, ship it with OR, and be done with it.

I've attached the file I use, which I created in 2006. With this file, I can have basically whatever smoke colour I want. I opt for a medium brown taken from a photo of a thick cloud of EMD 567 smoke.

 dieselsmoke.zip (21.14K)
Number of downloads: 392

If the OR team finds it satisfactory, they can include it from here on out if they want, I'm not very attached to it, it took no effort to make, it should yield the desired results, and I consider it public domain. On a related note, I think we should probably seriously consider creating a new global folder. One, because the contents of the MSTS one are garbage (especially the audio), and two, so that OR can further separate from MSTS.

[Eldorado.Railroad]

 Csantucci, on 22 October 2017 - 03:02 AM, said:

In my experimentation with activity randomizing I wanted to change color of the diesel exhaust simulating a compressor blowdown, but the color was always black.

Carlo,

Please look at this:
SIMISA@@@@@@@@@@JINX0D0t______

include ( ../AUnitSkin_LTV_4211.eng )

Engine (
ORTSDieselEngines ( 1
Diesel (
IdleRPM ( 270 )
MaxRPM ( 835 )
StartingRPM ( 2 )
StartingConfirmRPM ( 700 )
ChangeUpRPMpS ( 45 )
ChangeDownRPMpS ( 45 )
RateOfChangeUpRPMpSS ( 45 )
RateOfChangeDownRPMpSS ( 45 )
MaximalPower ( 1067kW )
IdleExhaust ( 1 )
MaxExhaust ( 1 )
ExhaustDynamics ( 1.2 )
ExhaustDynamicsDown ( 0.5 )
ExhaustColor ( 0000f9ff )
ExhaustTransientColor ( 40c4cfd2 )
ORTSEmergencyCausesPowerDown( 1 )
ORTSEmergencyCausesThrottleDown( 1 )
EmergencyEngagesHorn( 1 )
WheelSlipCausesThrottleDown( 1 )
MinOilPressure ( 40 )
MaxOilPressure ( 90 )
MaxTemperature ( 220 )
Cooling ( 13 )
TempTimeConstant ( 720 )
OptTemperature ( 70 )
IdleTemperature ( 60 )
)
)
)

This is in the added "openrails" folder for a given engine. IT DOES change colour, ExhaustColor ( 0000f9ff )..is a kind of "blue green". You can change it back to ExhaustColor ( 00eaf9ff ) for what I designed it for. Hope this helps.

Ciao,
Steve

[Csantucci]

I thank you all for the useful information and in particular ErickC for his generous offer.
@ Gerry and Steve: you see colours different from black because you not only did use the ORTSDieselEngines block, but also because you have replaced the original MSTS dieselsmoke.ace. If you re-insert the original dieselsmoke.ace, you will see black smoke even with the ORTSDieselEngines block. And so, replying to Gerry: OR does not use special code for the exhaust colours when you have the ORTSDieselEngines block: it only takes as base colors the ones found in such block instead of the ones that are hardcoded. But such colors are always multiplied with the ones within the dieselsmoke.ace file, and if you have black there ( 0 ) you can only get black.

So what is my actual idea, which aims at providing a decent smoke also in the default configuration (because not all people are like the readers of this forum, which like fiddling with .eng files and so on): using a widespread OR philosophy, OR would take as basis not the actual dieselsmoke.ace located within GLOBAL\TEXTURES, but a dieselsmoke.ace file within an Openrails subfolder within the GLOBAL\TEXTURES folder. If such file is not present, OR would take an internal dieselsmoke.ace, which could be selected among ErickC's one (thank you again, it's a good candidate) and other ones. It would be e.g. nice if 3dTrains allowed OR to use theirs.

Therefore I would proceed this way and ask the ORMT for an OK.

In a second moment I wonder if it could be wise to also insert within the "Correct questionable braking parameters" option, extended to "Correct questionable .eng parameters", some correction on questionable exhaust parameters, first of all the Nozzle diameter, which is fundamental in providing a nice diesel smoke and which is too small in many original .eng files.

[R H Steele]

Carlo, thank you for the explanation.
Looking at the screenshot...I have another question.
This is a loaded coal train climbing a grade (4 -lead engines - SD45R and 3 - SD40T2s, 4 helpers midtrain - SD40T2s and 90 loaded hoppers, ), full throttle. OR native physics used for both wagons and locomotives (OpenRails folder & ORTS Diesel Engine block). Default Activity is in a downpour and then it's a real slog up this grade.

Question: in this loading situation shouldn't the exhaust be poring out the stacks in a black column 10ft high or more? Why is it just white smoke wafting gently in the breeze?

[Ps - yes I have the 3DTrains Diesel Smoke aces and bat files installed...one of the first things I learned how to do 4 years ago...I had forgotten.]

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