Page 2 of 3 FirstFirst 123 LastLast
Results 11 to 20 of 24

Thread: Annotated ORTS Diesel Engine Block

  1. #11
    Join Date
    Jul 2006
    Location
    Decatur, IL
    Posts
    809

    Default

    Hi Gerry, nice work on your research!

    I want reiterate what I've said before about the Throttle/RPM tab. You can specify prototype RPM rates in Open Rails, but in most cases, this will cause the sounds to misbehave. Most MSTS engine sounds are based on the RPM of the engine, and MSTS did a poor job of accurately reflecting realistic RPM changes.

    In MSTS, throttle power and RPM are interlinked to the throttle position, meaning that moving the throttle lever to 12.5% gives you 12.5% of the total power and 12.5% of the max RPM. Moving the throttle lever to 25% gives you 25% of the total power and 25% of max RPM, etc.

    An EMD GP9 that really should remain at idle when in Run 1 is actually running at 70 RPM above idle in MSTS, and the sound of Run 1 is dependent upon the RPM being 70 RPM above idle. In Open Rails, when you make Idle and Run 1 the same RPM (difference of 1 RPM), the sounds don't understand that the throttle has moved. When you move the throttle to Run 2 with proto RPM data, the the MSTS sounds expect a 140 RPM increase from Idle, but the prototype has only increased 80 RPM.
    This causes MSTS sounds to not play sequentially Idle-8 in Open Rails in the same way it would in MSTS.

    Therefore, a compromise is needed. The way to work around this fault is to match the RPM increases in the ORTSDieselEngine with the "EXPECTED" RPM increases of the MSTS sound pack. A default locomotive like the GP38 has a Throttle that has an even 12.5% increase with every position, and the sound is set up to match that throttle increase. BLW locomotives that start at 5% in an attempt to provide a more prototypical power curve have a different RPM curve. In Open Rails, you would have to set the Throttle/RPM Tab up differently for these two models to achieve the best sounds.

    What has worked for me is to first figure out what throttle curve the original sound set was built to, i.e. is it the default 12.5%, the BLW 5%, or something else. Once that has been determined, I subtract the minimum RPM from the maximum RPM and get a base RPM range to work with. Then, it's a process of using the percentages in the matching Throttle control section of the .eng file multiplied by the RPM base range to get each RPM increase for each throttle notch in the Throttle/RPM Tab. (For GP9: 835-275=560x0.125=70+275=345 RPM for Run 1. 560x0.25=140+275=415 RPM for Run 2, etc....)
    This method preserves the function of MSTS sounds, but has a few side effects. The loco will smoke a bit going from Idle to 1 and fuel consumption rates will be slightly changed in the middle notches.

    Another option is to directly edit the sound .sms files, but I don't have any knowledge of that so I compromise the RPM instead.

    EDIT: You have to be careful not to mistake a revised Throttle control section for the original. Turbo Bill's ProPack 4 and 5 have brake/throttle percentages to simulate proto power curves, and I've used them to upgrade some of my locomotives. Though these are a good physics replacement, they can also mess with the sounds for the reasons described above. However, you can use these power curves in your ORTSDieselEngine section by multiplying the throttle percentages by the maximum power in watts to get the entries for the RPM/Power Tab.

    Tyler
    Last edited by tbundy1982; 01-12-2018 at 11:45 AM.

  2. #12
    Join Date
    Feb 2013
    Location
    known universe
    Posts
    1,263

    Default

    Quote Originally Posted by derekmorton View Post
    That sounded a bit snappy. I need to tone it down a bit.

    In my testing I have used kw and hp and it doesn't seem to matter.
    I have just added a kw column to my spreadsheet next to the hp column so I can use either figure.
    The HUD has kw on it so I will have to use kw.

    The point I was trying to make was the flywheel hp, I use that term loosely, could be kw, I should have said power, while you were trying to make your point about the manual stating watts.
    Derek, first off, My apologies, any "snappy tone" was a reflection of my post, which definitely started the ball rolling. I posted out of frustration trying to understand. No excuse for that. Let me carefully read the whole thread, and I'll post some coherent remarks then.
    Best regards, Gerry
    Cheers, R. Steele [Gerry] It's my railroad and I'll do what I want! Historically accurate attitude of US Railroad Barons.


  3. #13
    Join Date
    Feb 2013
    Location
    known universe
    Posts
    1,263

    Default

    Quote Originally Posted by tbundy1982 View Post
    Hi Gerry, nice work on your research!

    I want reiterate what I've said before about the Throttle/RPM tab. You can specify prototype RPM rates in Open Rails, but in most cases, this will cause the sounds to misbehave. Most MSTS engine sounds are based on the RPM of the engine, and MSTS did a poor job of accurately reflecting realistic RPM changes. ...Tyler
    Thank you Tyler, coming from you, means a lot. I just don't have as much experience or knowledge about this as yourself, especially regarding the difference between MSTS and OR in handling the same sound files. To my tin ear, the ORTS engine block sounds just fine. Unbelievable, I know..and I do believe what you are saying...I just cannot hear it...give me 12 years of experience, like yourself, I just may begin to hear it.
    Is it the OR code interpreting the sound files, or the construction of the files themselves - PLUS - how the ORTS diesel engine block is constructed...Am I even in the same neighborhood as the ballpark?

    I'm going to have to read your post through several times, before I get some accurate sense of what you are saying, sorry 'bout that.
    Cheers, R. Steele [Gerry] It's my railroad and I'll do what I want! Historically accurate attitude of US Railroad Barons.


  4. #14
    Join Date
    Jun 2004
    Location
    Hastings, MN, 55033
    Posts
    3,433

    Default

    Oh, hey, Tyler, I've been meaning to PM you. I'm in the late stages of solving the 645AC/BC/C sound problem permanently (I just need to create some reworked SMS files for the AC/BC running at 800 RPM instead of the C's 835). Then there won't be need for any compromises. Want to test some aural garbage?
    Last edited by Erick_Cantu; 01-13-2018 at 01:25 AM.

  5. #15
    Join Date
    Jul 2006
    Location
    Decatur, IL
    Posts
    809

    Default

    Hi guys,

    Eric, I would certainly be happy to help if I can. Shoot me an email, found in one of my Readmes, or send a PM.

    Gerry, sorry about the complicated post. I realize that it's a lot of information. I'd be happy to explain if you have questions.

    The original problem is one caused by MSTS. RPM in MSTS is based on the Throttle percentages. Since most sounds were designed for MSTS, they are designed to interpret MSTS's non-prototype RPM modeling. When you add prototype RPM data in the ORTSDieselEngines section, sounds in the .sms get confused because they were expecting the old MSTS RPM rates instead of the new ORTS corrected RPM rates.

    As I said, another option is to alter the .sms sound files, but I really don't know what I'm doing there yet. You essentially have to tell the sounds (within the .sms) to play within a certain RPM range. That allows the different throttle positions to produce different sounds. When that RPM range is changed in the .eng file, the sounds get confused because the "EXPECTED" RPM range is not there. You can get some really funky sound response with this, skipping notches or not changing sound when you move the throttle.

    You have to match the RPM to the sounds or vice versa for everything to work correctly. In MSTS, this was as simple as matching the Throttle position percentages to the sound files or vice versa. With the ORTSDieselEngines data, we can dictate the RPM for each throttle position; this RPM data is what affects the sounds, not the throttle position or power output. I think the Variable2 found in the .sms files is engine RPM. Unfortunately, my knowledge and experience ends there.

    Again, my RPM compromise detailed previously comes from the lack of knowledge in editing sounds. It's the cheapest fix I could think of that can be implemented with minimal side-effects.

    EDIT: My example of a GP9 RPM range is different than the GEVO diesel section in the OP. Newer locomotives like the GEVO have a low idle, where an older GP9 has no low idle feature. The GEVO has 9 engine speeds and sounds, the GP9 only has 8. Idle and 1 are the same speed, and virtually the same sound, though I've been on locomotives that change sound slightly when going from Idle to 1 when the load is applied.

    Tyler
    Last edited by tbundy1982; 01-13-2018 at 04:09 PM.

  6. #16

    Default

    Quote Originally Posted by derekmorton View Post
    Traction horsepower = hp going to the wheels.
    Gross hp = hp at the flywheel.

    OR needs HP at the flywheel.
    I have been using traction horsepower and since reading this I have tried to look for actual gross horsepower for the modern diesels with no success. I used to have GE specs in pdf from their site but no longer available. Anyone with gross horsepower for modern diesels like SD60 - SD70ACe? Thanks for the info on the horsepower Derek.

  7. #17

    Default

    Ultimately, the answer is going to be to create OR-specific .sms files that DO tie the prime over sounds directly to prime mover RPM and behavior. I've lobbied for this for a long time because, in addition to the benefits outlined above in this thread, RPM-drive prime mover sounds would allow for things like the high-idle feature of the EMD 710 prime mover (where the prime mover can automatically move to and from high idle when certain operating parameters--e.g., coolant temperature--go out of or back into a specified range), enabling the .sms file to understand Automatic Engine Start Stop (AESS, where the prime mover can shut itself down and restart automatically), or putting a locomotive into or out of HEP mode. In many cases, the actual .wav files are already existent to do a lot of that, it's just the challenge of writing the code so that OR could interpret it.

    OR can already do things with existing MSTS files that MSTS can't. One example is the air compressor. Countless MSTS .sms files don't have a "real" compressor sound stream, just a random compressor sound stream--presumably to emulate that locomotive air compressors start periodically when the main air reservoir pressure drops from train line and other leaks. Well, TrainPipeLeakRate, an existing but unimplemented feature in MSTS, works in the player locomotive of an .eng file used in OR. So, one can program a modest TrainPipeLeakRate in the .eng file, and a "real" air compressor sound stream in the .sms file will happily play every so often when the train pipe leak drops the air reservoir pressure enough to cause the compressor to start.

    The other big problem, and one that some of the posters in this thread are bravely tacking, is that many content creators just get lazy when writing .eng and .sms files. A good example, is the discussion about the 567 GP-9's not moving off of idle prime mover RPM in Run 1. That's true of that locomotive, but that "feature" has been programmed into numerous other locomotive models' .eng and .sms files where that simply isn't true. Admittedly, some information on locomotive model behavior can be difficult to come by, but a lot of less-than-perfect stuff get put out there just because model creators may be more interested in the model itself and not so much interested in how it actually emulates the prototype in simulation. Again, sort of the difference between a "game" and a simulator.

  8. #18
    Join Date
    Nov 1999
    Location
    Eltham, Australia.
    Posts
    6,356

    Default

    The es44 quotes 4400/4520 and the ac6000 quotes 6000/6250.
    The sd90mac-h quoted 6000/6250 as well.

    I suspect that the 6250 was to claim the highest power and therefore a marketing number.
    I would tend to go for the 4400/4520 as being reasonable.

    You can check on power at the wheels in the HUD and make up your own mind.

    For me that means an extra 120hp or 90kw
    Cheers
    Derek

  9. #19
    Join Date
    Feb 2013
    Location
    known universe
    Posts
    1,263

    Default

    Quote Originally Posted by wwhall View Post
    Ultimately, the answer is going to be to create OR-specific .sms files that DO tie the prime over sounds directly to prime mover RPM and behavior. I've lobbied for this for a long time because, ...
    Thank you, that helped push forward my understanding of sms files - keep lobbying!!
    Perhaps, write a basic OR sms file for a default locomotive, GEVO, Dash9, SD40?? Someone, anyone.
    Cheers, R. Steele [Gerry] It's my railroad and I'll do what I want! Historically accurate attitude of US Railroad Barons.


  10. #20
    Join Date
    Feb 2013
    Location
    known universe
    Posts
    1,263

    Default

    Quote Originally Posted by Erick_Cantu View Post
    Oh, hey, Tyler, I've been meaning to PM you. I'm in the late stages of solving the 645AC/BC/C sound problem permanently (I just need to create some reworked SMS files for the AC/BC running at 800 RPM instead of the C's 835). Then there won't be need for any compromises. Want to test some aural garbage?
    Hey Erick ( you are always doing something useful ) are going to write sms files for OR with specific OR triggers? That would be cool.
    Cheers, R. Steele [Gerry] It's my railroad and I'll do what I want! Historically accurate attitude of US Railroad Barons.


Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •