[darwins]

Is the second parameter in the MaxVelocity statement used in OR?

If so what exactly is the difference between

MaxVelocity ( 29.06 1.00 )

and

MaxVelocity ( 29.06 0.50 )

?

Is there any way to calculate or estimate what the second parameter should be for a consist?

[For MSTS it often came down to trial and error using the activity editor, hopefully OR has improved on this!]

The Manual explains that the maximum speed of AI trains is governed by a number of factors.

There is no mention of the second factor in the MaxVelocity statement.

Do gradients influence the performance of AI trains? (This is actually quite important if you are following one up a hill!)

[R H Steele]

Max Speed and Consists <<< so many threads it's understandable forgetting about this one.

Just reread -- and post#28 by SteamerCtn, and other posts in the above referenced thread from January 13, 2020 appear to provide the answers to your questions.

Because it was so informative I have kept it earmarked for reference. Would be good to get a solid affirmative statement on how OR ( or if? ) handles this MSTS parameter in current code.

[cr-stagg]

Yes, there is an equation. I reverse engineered the MSTS CE to create the specifications for the Visual Basic code to add the feature to ConBuilder. That was one of the reasons ConBuilder became payware.

The payware version of ConBuilder Will create consist MaxPower ( ##.### 0.### ) or MaxPower ( ##.### 1.00 ) the same as the MSTS CE. However, the versions of ConBuilder that were/are not Payware will always create consists with MaxPower ( ##.### 1.00 ) unless the user enters his own values when given the opportunity of doing so.

FYI opening a consist with MSTS-CE, ConBuilder payware version or the TSRE-CE, deleting a WAG then adding the same WAG back to the consist, and saving the file will result in a correctly calculated Consist MaxPower entry.
Conversely editing a consist file with a freeware version of ConBuilder will result in the entry for MaxPower as ( ##.### 1.000 ) even if the original consist had a MaxPower ( ##.### 0.### ).

[cr-stagg]

If OR does use Consist MaxVelocity, how does it calculate it when a consist is modified during the game?

[Laci1959]

Quote

The Manual explains that the maximum speed of AI trains is governed by a number of factors.

Hello.

AI trains were used in MSTS. That was their maximum speed. If the second number was 0.75, then three-quarters of the first number was the maximum speed of the AI. Even if there was a speed post ( Speedpost ) on the course. They did NOT keep those restrictions. Many tracks therefore used invisible markers instead of speed limits. The speed limit given by the signal was also observed by the AI trains.
Although it shouldn't be, I always set it to 1.

Sincerely, Laci1959

[darwins]

cr-stagg, on 19 November 2022 - 07:16 PM, said:

If OR does use Consist MaxVelocity, how does it calculate it when a consist is modified during the game?

That is an interesting question.

ORTS really does need to have some way to handle things like this (even if it does not already).

So the present situation is:

https://i.imgur.com/7bsUq9Z.jpg


Some things are not clear.

What happens if MaxVelocity = 40?

Where is the reference <operation-performance>? It does not appear anywhere in the Manual, nor does there appear to be any external link.

After doing a test activity, it appears that the second parameter is ignored by OR.

MaxVelocity ( 33.9 1.0 ), MaxVelocity ( 33.9 0.5 ) and MaxVelocity ( 33.9 0.0 ) all give the same results.

However, the second parameter must be present. OR can not read a consit file that says MaxVelocity ( 33.9 ) or MaxVelocity ( ) or a consist file that has no MaxVelocity statement at all.



Even without looking in detail at tractive force curves or steam loco performance a number of factors could be used to give better physics:

Input (or Calculated) MaxPower from all eng files. [Assume this to apply at all speeds for diesel and electric, use a factor maybe 0.75 for steam.]
Total Train Resistance (Davis A, B and C values) from all eng and wag files. = Rolling Resistance + Air Resistance = Acceleration
Gross Mass from all eng and wag files. = Gradient Resistance
Total Max Brake Force from all eng and wag files. = Deceleration

Max Velocity should be the lowest of all the factors currently listed, except that for any train the AI trains should be limited by the maximum permitted speed of the vehicle with the lowest maximum permitted speed.
Once again it comes back to a plea to be able to add ORTSMaximumPermittedSpeed to the wag section of any eng or wag file, such that this would override any higher value for the consist elsewhere.

In the beginning the excitement of OR was to have realistic physics for AI trains. (Including being slowed by gradients!) Then all this was swept aside by the need for MSTS activities to work just like they did in MSTS. Will we at some point in the future have an OR consist format that ignores the old MSTS factors and allows AI trains in both activity and timetable mode to behave more realistically?

[Weter]

Performance was seen in MSTS AE timetable form.
Timetable mode gives much more variations in AI trains behavior.
Though, that's exactly behavior, as physics themselves for AI are simplified.

Computing of all AI train's physics will be a challenge for player's hardware.

[darwins]

Weter, on 20 November 2022 - 05:40 AM, said:

Computing of all AI train's physics will be a challenge for player's hardware.

Hopefully someone will come up with an approximation that is simpler than the player train physics, but more realistic that what we have now. $acc and $dec in timetable mode are a great idea, but some variation with gradient and curves should also be involved.

[Weter]

That's fact.

There are many: random delays, priority, speed maintaining behavior. Etc...