[Traindude]

steamer_ctn, on 29 June 2023 - 10:31 PM, said:

In the latest Unstable version I have released changes to allow multiple steam engines to be added to a locomotive.

NOTE: This is very much a work in progress, and only addresses the physics at the moment. Visual and audio effects will follow at a latter stage. Also some parameters in the ENG file may change as development progresses.

To see how it works download the PRR T1 from my site and give it a go. The T1 has been configured with three steam engines, the two duplex ones, and a steam booster.

These changes required a significant change to the steam code so it is possible that some bugs may have been introduced. If you think that you have found a bug, then test with the appropriate CTN model, and then bring it to my attention so that I can debug it.

The T1 was working fine up until U2023.07.02-1022. After the update, I'm not able to view the individual steam chest pressures on the extended HUD (yes, I am using the advanced/duplex model), and I'm no longer able to control the booster with CTRL+W and SHIFT+W.



Additionally, the extended HUD also displays the wrong wheel arrangement for the engine--mislabeling it as a 4-8-4 instead of the true wheel arrangement of 4-4-4-4.

[steamer_ctn]

Traindude, on 02 July 2023 - 11:42 PM, said:

The T1 was working fine up until U2023.07.02-1022. After the update, I'm not able to view the individual steam chest pressures on the extended HUD (yes, I am using the advanced/duplex model), and I'm no longer able to control the booster with CTRL+W and SHIFT+W.

It looks like another PR has been added to the Unstable version, and "kicked" this PR out of the Unstable version, so it will not work until I work out where the conflicts are.

Traindude, on 02 July 2023 - 11:42 PM, said:

Additionally, the extended HUD also displays the wrong wheel arrangement for the engine--mislabeling it as a 4-8-4 instead of the true wheel arrangement of 4-4-4-4.

Thanks I will have a look at this.

[Traindude]

Thank you for reinstating the duplex and booster functionality. One odd side effect that I'm noticing is the lack of exhaust chuffs when the booster isn't engaged. I viewed thw sound debug window (ALT+S) while operating the T1, and sure enough, the "Variable2" readout (throttle percentage) only increases and decreases as the booster is engaged with CTRL+W and disengaged with SHIFT+W. Opening or closing the main throttle while the booster is off causes the Variable2 readout to stay at zero.

On a side note, when the PR for the duplex/booster functionality was temporarily unavailable, it seemed the constant low superheat bug was gone, and the "Current Superheat" value increased or decreased with throttle opening as it should, but when the duplex/booster function was restored, the constant low superheat bug reappeared.

[cesarbl]

Regarding the implementation of visual effects, in particular wheels spinning at different speeds, my proposal is to couple together shape file animations corresponding to the same wheelset:

Axle(
    WheelRadius ( 0.8m )
    WheelWeight ( 60t )
    NumberWheelAxles ( 3 )
    AnimatedParts ( WHEELS1 WHEELS2 WHEELS3)
)
Axle(
    WheelRadius ( 0.5m )
    WheelWeight ( 20t )
    NumberWheelAxles ( 2 )
    AnimatedParts ( WHEELS11 WHEELS12 WHEELS21 WHEELS22 )
)

In this example, some of the wheel parts in the shape file will be animated with speed from the first engine, and others will be animated with the second engine. The key parameter is AnimatedParts(), to be inserted in the Axle() block.

I'm not an expert in 3D modelling, so is this approach OK?

[darwins]

That idea looks good.

I think there is a case to put this in the wag part of the file. This is because on many steam locomotives, the leading wheels and trailing wheels were of different diameters.
One more valuable addition would be to include within the block information about which axles are braked and which axles are not braked.

So for a steam loco that has bogie brakes for the leading wheels, but no brakes for the trailing pony truck we might get:

Axle(
	WheelRadius ( 0.45m )
	WheelWeight ( 21t )
	NumberWheelAxles ( 2 )
	AnimatedParts ( WHEELS11 WHEELS12 )
	WheelsBraked ( 1 )
)
Axle(
	WheelRadius ( 1.00m )
	WheelWeight ( 67t )
	NumberWheelAxles ( 3 )
	AnimatedParts ( WHEELS1 WHEELS2 WHEELS3 )
	WheelsBraked ( 1 )
)
Axle(
	WheelRadius ( 0.55m )
	WheelWeight ( 16t )
	NumberWheelAxles ( 1 )
	AnimatedParts ( WHEELS21 )
	WheelsBraked ( 0 )
)

For the 1Co-Co1 diesel electric loco on the CTN website we would get:

Axle(
	WheelRadius ( 18.5in )
	WheelWeight ( 23.3t-uk )
	NumberWheelAxles ( 2 )
	AnimatedParts ( WHEELS11 WHEELS24 )
	WheelsBraked ( 0 )
)
Axle(
	WheelRadius ( 21.5in )
	WheelWeight ( 109.5t-uk )
	NumberWheelAxles ( 6 )
	AnimatedParts ( WHEELS12 WHEELS13 WHEELS14  WHEELS21 WHEELS22 WHEELS23 )
	WheelsBraked ( 1 )
)

I am not sure if in the code there is any issue distinguishing which parts are animated in the shape file as opposed to axles automatically animated by OR.

[cesarbl]

Quote

One more valuable addition would be to include within the block information about which axles are braked and which axles are not braked.

So for a steam loco that has bogie brakes for the leading wheels, but no brakes for the trailing pony truck we might get:

Yes, that's definitely something to implement. I suggest using BrakeFraction ( % of total brake force ) instead of WheelsBraked ( 1 ). Some wheels may have more powerful brakes than others.

Quote

I am not sure if in the code there is any issue distinguishing which parts are animated in the shape file as opposed to axles automatically animated by OR.

Currently WHEELSxx are animated automatically, while WHEELSx are be animated using the shape file (if an animation exists).

[darwins]

At the moment we divide the file with non-driven wheels in the wag section and driven wheels in the eng section. Would it be more logical to divide the Axle ( ) entries in the same way? Although this is intended for animation, it could perhaps replace

Wag (
ORTSNumAxles ()
WheelRadius ()
)
Eng (
ORTSNumDrivingAxles ( )
WheelRadius ( )
ORTSDriveWheelWeight ( )
)

As it is the same data.

[cesarbl]

The idea is to define everything at the Wagon() section. The difference between driven and not driven wheels is that the former will be attached to a SteamEngine()

[Laci1959]

Hello

Why this racial discrimination?

All over Europe, diesel and electric locomotives and railcars where not all axles were driven were produced.
Anyway, I'll be very happy if it finally comes to fruition.
Thank you very much in advance.

Sincerely, Laci 1959

[cesarbl]

What do you mean? The idea is that both driven and not driven axles are defined in the same way.