Union Pacific FEF-3 4-8-4 Northern type steam locomotive, by Smokebox

[mrennie]

Is it possible to start looking forwards towards the actual animation and simulation of UP 844? The sights and sound that make her come to life in our sims?

She has twin exhaust stacks, but TS2013 doesn't allow for more than one synchronized smoke emitter.
The typical towering exhaust of US steam locomotives accelerating under full power with wide open throttle hasn't been captured very well before either, since there is no emitter parameter that controls speed of emission.

Actually there is (V int velocity as an x, y, z vector, with variance and gravity, and then there's the emission rate, the roll-off rate, velocity variance, resistance, spread vector and many more), but it's quite a balancing act to get all the various parameters to work properly together. It took me ages, and many attempts, to get something satisfactory last time around.

Cylinder cocks also emit steam synchronized with the driving wheels' rotation, again I think impossible with the current emitters. Unless one tries to script one's own "single shot" emitters and synchronizes them with the motion oneself.

Impossible???? I suspect you haven't got the Consolidation

Hot water gushing from the live steam injector being primed?

And steam gushing from the overflow when you pull the pick-up injector lever without having first primed it with water from the tender. Again, this is all in the Consolidation already.

Sand dust when sanding (not really necessary in a passenger engine, as opposed to Big Boy climbing Sherman Hill for instance)?

Again, the Consolidation already has that

Capturing sounds off the real 844 wouldn't be that much of a problem with all the folks here having taped her or even with access to the real loco.

Still, a model of this quality needs this attention to details like the above to top it off.

I recommend you try out the Connie.

The FEF-3 will have even more surprises for you.



Mike

[mrennie]

One more thing about the main stack particle emitter. It's possible to have more smoke than I put into the Connie, but it has a big hit on frame rates if you overdo it. I started out with a lot more smoke, which looked fabulous (if only I'd kept the screenshots ... oh well), but as I added more detail to the actual model, I decided to trade off stack smoke to maintain the fps. It's also why I went as far as having the emissions from the cylinder cocks depend on just how much you pull the lever - if your system can't handle the maximum amount (which you reach with the throttle wide open and the lever pulled back all the way), you can reduce the amount of steam particles by closing the cylinder cocks partially.

That said, I do intend to make a bespoke particle emitter for the FEF-3's stack - I won't just reuse stuff from the Connie if they don't look right on the Northern.

[_o_OOOO_oo-Kanawha]

Good to hear you've tackled the lot in your Consolidation.

No, Mike, I don't have it, so I don't know about your achievements. I am first and foremost interested in big, modern US steam locomotives (that aren't MSTS conversions).
Big Boy and Challenger are somewhat simplyfied and no longer developed. The Pennsy K4 is a step in the right direction by RSC, but hasn't been followed up yet by more essential PRR steam locomotives.

So your FEF-3 is first on my list and I'll buy it, no matter the inevitable small concessions. I am sure it is a favourite with most of the US TS2013 players.

My reference to the particle emitters was about the lack of scripting 'handles'. Controlling those emitters is like dark magic, as there is hardly information on them. Either from RSC or in the fora. AFAIK, only density and colour parameters can be scripted, not volume or speed of the exhaust. I understand that particle dynamics is an FPS killer when overdone.
Oil fired engines do have different smoke from coal fired ones. Smoke from that Bunker C grade oil is very heavy and greasy and will soil an engine quickly.
Perhaps 844, the FEF-3 in excursion service has been converted to burn lighter, cleaner oil to meet EPA/FRA standards?

Anyway, I'll see what the FEF-3 has to offer when she'll be ready and for sale to the public.

[mrennie]

My reference to the particle emitters was about the lack of scripting 'handles'. Controlling those emitters is like dark magic, as there is hardly information on them. Either from RSC or in the fora. AFAIK, only density and colour parameters can be scripted, not volume or speed of the exhaust.

That's right, those are the only things you can control from the LUA scripts, the rest of the parameters are statically defined in the blueprints and can't be changed in-game. You can also, of course, enable and disable them from the script.

[PapaXpress]

That's right, those are the only things you can control from the LUA scripts, the rest of the parameters are statically defined in the blueprints and can't be changed in-game. You can also, of course, enable and disable them from the script.

AH-HA!

ok... keep talking... I'm listening.

[UP3985]

That last image was of UP 828. (An FEF-2 I believe?) The 844 looks quite different than that. I think it looks quite dashing without the gyralite, or smoke deflectors!

[mrennie]

AH-HA!

ok... keep talking... I'm listening.

OK Some examples ...

In the first call to Update, I get the default emission rates for the emitters:

Code: Select all

gEmitRateMain = Call("Main Smoke Stack:GetEmitterRate");

By the way, that name is important. Originally, I used my own name for the smoke particle emitter and began trying to synchronise it to the piston strokes myself in the LUA script, until I found out that the core programme does it for you if you use that name "Main Smoke Stack" for the emitter.

Then I enable it:

Code: Select all

Call ( "Main Smoke Stack:SetEmitterActive",1);

Because the loco begins the scenario standing still, there's no smoke even though the emitter is active, thanks to that programming in the core code.

Also, in every call to Update, I modify the colour depending on the current tractive effort:

Code: Select all

   
        TractiveEffort = Call ( "GetTractiveEffort" );
   TractiveEffort = math.abs ( TractiveEffort );
   
   if TractiveEffort < cMaxTE/10 then
      gSmokeColourR = 0.8
      gSmokeColourG = 0.8
      gSmokeColourB = 0.8
   end   
   
        if ( TractiveEffort <= cMaxTE/2 ) and ( TractiveEffort >= cMaxTE/10 ) then
      gSmokeColourR = 0.5
      gSmokeColourG = 0.5
      gSmokeColourB = 0.5
   end
      
   if TractiveEffort > cMaxTE/2 then
      gSmokeColourR = 0.25
      gSmokeColourG = 0.25
      gSmokeColourB = 0.25
   end   
   
   Call ( "Main Smoke Stack:SetEmitterColour", gSmokeColourR, gSmokeColourG, gSmokeColourB );



cMaxTE is a constant I define at the beginning of the LUA script:

Code: Select all

cMaxTE = 0.5

There's some fancy scripting to determine whether to shut off the smoke emitter, which results in setting a variable called smoke (0 means disable):

Code: Select all

        if smoke == 0 then
       Call ( "Main Smoke Stack:SetEmitterRate", 100000); --  OFF
    else
       Call ( "Main Smoke Stack:SetEmitterRate", gEmitRateMain);
    end;


The way you disable an emitter is to set its rate to a very high value, which effectively makes it use up its quota of particles. To make the particles more or less dense, you play with the parameter of SetEmitterRate ... making it a smaller value increases the density. However, every particle emitter is different, so you have to experiment a lot to find the sweet spot.

[mrennie]

That last image was of UP 828. (An FEF-2 I believe?) The 844 looks quite different than that. I think it looks quite dashing without the gyralite, or smoke deflectors!

Excellent photos! Thanks :)

I see the front coupling housing cover was different back then. I didn't know that .... something else to watch out for in the 1940s version.

[UP3985]

Here's another side view I've come across.

[mrennie]

Here's another side view I've come across.

That's the one I have in a book by J. Parker Lamb ("Perfecting the American Steam Locomotive").

[mrennie]

I also realised that the speedometer sensors attached to the axles of the trailing truck came later, so I'll have to modify that too for the 1940s version.

[UP3985]

And another with her as a coal burner. (and no skirting around the stacks? I'd say just ignore that) This, looks weird.

[bpetit]

Well No. 844 uses No. 6 oil.

[GLRX12]

If you look at that picture.....you will see a nice big pile of coal in the tender

844 was delivered as a stoker fired coal burner. It was very quickly converted to oil however, and has never switched back since, although it no longer burns no. 6, its basically used motor oil now....like pretty much every steam operation. And if anyone has lots of used motor oil, its UP.

We have pumped the oil from the 1203 directly into the tank of Shay 9 before, burns just fine in a pinch!

[_o_OOOO_oo-Kanawha]

That last image was of UP 828. (An FEF-2 I believe?) The 844 looks quite different than that. I think it looks quite dashing without the gyralite, or smoke deflectors!

This is presumably an official ALCo photo with 844 ready to be delivered to UP. Noticed the covered/protected headlight and numberboards.

And another with her as a coal burner.



(and no skirting around the stacks? I'd say just ignore that) This, looks weird.

Indeed, those exposed stacks look weird to me too.
The smoke deflectors are perfectly flat here still.

Also, notice the amount of superelevation!

Back to topic, 844 went through quite a few small modifications during her service life probably, making any model a compromise.
However, with a sensible approach to "kit building", any variation can be produced by Mr. Rennie.