Coals to Newcastle

Visual Effects

Aim - this section provides an overview of the typical operation of special visual effects, which could include steam or smoke on the steam locomotive and wagons, and describes how to define these effects in Open Rails (OR) WAG and ENG files.

Index

Overview of Key Visual Effects

Steam Locomotives

The ancillary devices on a steam locomotive, such as the air compressor and water injectors are typically powered by steam from the boiler. Steam for these devices is piped around the locomotive. Thus, a steam locomotive can have steam exhausting from it at various locations. Using a NSWGR P Class (C32) locomotive as an example the principal steam powered devices are shown in the diagram below, and their basic operation described.

Visual Effects Code - Structure and layout in Open Rails

Steam Locomotives

Steam exhausts on a steam locomotive can be modelled in OR by defining appropriate steam effects in the SteamSpecialEffects section of the ENG file. Each effect has a name which must be included in the ENG file, and these names are shown in the following section.

OR supports the following special steam effects on steam locomotives:

• Stack (named StackFX) - represents the smoke stack emissions. This effect will appear all the time in different forms depending upon the firing and steaming conditions of the locomotive.
• Stack - Engine #1 or default - (named CylinderSteamExhaust1FX, CylinderSteamExhaust2FX, CylinderSteamExhaust3FX, CylinderSteamExhaust4FX) - represents the steam exhausted out of the stack (which gives the steam locomotive its "puffing" appearance. There is one effect for each steam cylinder, and the exhaust is timed to the cylinders operation.
• Stack - Engine #2 - (named CylinderSteamExhaust2_1FX, CylinderSteamExhaust2_2FX, CylinderSteamExhaust3FX, CylinderSteamExhaust4FX) - represents the steam exhausted out of the stack (which gives the steam locomotive its "puffing" appearance. There is one effect for each steam cylinder (assumed that second engine only has two cylinders), and the exhaust is timed to the cylinders operation.
• Stack - Booster Engine - (named BoosterCylinderSteamExhaust01FX, BoosterCylinderSteamExhaust02FX - represents the steam exhausted out of the stack (which gives the steam locomotive its "puffing" appearance. There is one effect for each steam cylinder (assumed that the booster engine only has two cylinders), and the exhaust is timed to the cylinders operation.
• Steam cylinder Cocks - Engine #1 or default - (named Cylinders11FX and Cylinders12FX, Cylinders21FX and Cylinders22FX, Cylinders31FX and Cylinders32FX, Cylinders41FX and Cylinders42FX), where CylindersyzFX, y = cylinder number, and z = exhaust point- two effects are provided for each cylinder which will represent the steam exhausted when the steam cylinder cocks are opened. The effects are provided to represent the steam exhausted at the front and rear of each piston stroke. These effects will appear whenever the cylinder cocks are opened, and there is sufficient steam pressure at the cylinder to cause the steam to exhaust, ie, when the regulator is open (> 0%).
• Steam cylinder Cocks - Engine #2 - (named Cylinders2_11FX and Cylinders2_12FX, Cylinders2_21FX and Cylinders2_22FX, where Cylindersx_yzFX, x = engine number, y = cylinder number, and z = exhaust point - two effects are provided for each cylinder which will represent the steam exhausted when the steam cylinder cocks are opened. The effects are provided to represent the steam exhausted at the front and rear of each piston stroke. These effects will appear whenever the cylinder cocks are opened, and there is sufficient steam pressure at the cylinder to cause the steam to exhaust, ie, when the regulator is open (> 0%).
• Booster cylinder Cocks - Engine #1 or default - (named BoosterCylinders11FX and BoosterCylinders12FX, BoosterCylinders21FX and BoosterCylinders22FX, where BoosterCylindersyzFX, y = cylinder number, and z = exhaust point- two effects are provided for each cylinder which will represent the steam exhausted when the steam cylinder cocks are opened. The effects are provided to represent the steam exhausted at the front and rear of each piston stroke. These effects will appear whenever the cylinder cocks are opened, and there is sufficient steam pressure at the cylinder to cause the steam to exhaust, ie, when the regulator is open (> 0%).
• Air compressor (named CompressorFX) - represents a steam leak from the air compressor. Will only appear when the compressor is operating.
• Turbo-generator (named GeneratorFX) - represents the emission from the turbo-generator of the locomotive. This effect operates continually. If a turbo-generator is not fitted to the locomotive it is recommended that this effect is left out of the effects section which will ensure that it is not displayed in OR.
• Whistle (named WhistleFX) - represents the steam discharge from the whistle.
• Safety valves (named SafetyValvesFX) - represents the discharge of the steam valves if the maximum boiler pressure is exceeded. It will appear whenever the safety valve operates.
• Water injectors (named Injectors1FX and Injectors2FX) - represents the steam discharge from the steam overflow pipe of the injectors. They will appear whenever the respective injectors operate. Injector 1 is normally operated by the Fireman and is the main Injector in use.
• Steam ejectors (named SmallEjectorFX and LargeEjectorFX) - represents the steam discharge from the steam ejectors associated with vacuum braking. They will appear whenever the respective ejectors operate.
• Boiler blowdown valve (named BlowdownFX) - represents the steam discharge from the boiler when the blowdown valve is opened.
• Tracke Sanding System - typically for steam locomotives (named SanderSteamExhaustForwardFX and/or SanderSteamExhaustReverseFX) - represents the steam discharged from the sanding system when sanding is turned on.

NB: If a steam effect is not defined in the SteamSpecialEffects of the ENG file, then it will not be displayed in the simulation. If the effect is defined but all the direction parameters are set to zero the effect will not be displayed.

The typical structure of the visual effects section for a steam ENG files is as follows:

Effects (      
   SteamSpecialEffects (
                  

   Effect Name (
                           Effect location
                           Effect direction
                           Effect nozzle width
                     )
           )
       )

Note: It is important to ensure that the opening and closing brackets for the effects section match up, otherwise errors maybe generated.

Diesel Locomotives

Various exhaust effects on a diesel locomotive can be modelled in OR by defining appropriate effects in the DieselSpecialEffects section of the ENG file. Each effect has a name which must be included in the ENG file, and these names are shown in the following section.

OR supports the following special visual effects on diesel locomotives:

• Exhaust (named Exhaustnumber) - is a diesel exhaust. Multiple exhausts can be defined, simply by adjusting the numerical value of the number after the key word exhaust.

NB: If a visual effect is not defined in the DieselSpecialEffects of the ENG file, then it will not be displayed in the simulation. If the effect is defined but all the direction parameters are set to zero the effect will not be displayed.

The typical structure of the visual effects section for a diesel ENG files is as follows:

Effects (      
   DieselSpecialEffects (
                  

   Effect Name (
                           Effect location
                           Effect direction
                           Effect nozzle width
                     )
           )
       )

Note: It is important to ensure that the opening and closing brackets for the effects section match up, otherwise errors maybe generated.

Wagons

Various exhausts on a wagon can be modelled in OR by defining appropriate visual effects in the SpecialEffects section of the WAG or ENG file. Each effect has a name which must be included in the file, and these names are shown in the following section.

OR supports the following special visual effects on wagons:

• Steam Heating Boiler ( named HeatingSteamBoilerFX) - represents the exhaust for a steam heating boiler. Typically this will be set up on a diesel or electric train as steam heating was provided directly from a steam locomotive.
• Wagon Generator ( named WagonGeneratorFX) - represents the exhaust for a generator. This generator was used to provide additional auxiliary power for the train, and could have been used for air conditioning, heating lighting, etc. Currently operates continuously.
• Wagon Smoke ( named WagonSmokeFX) - represents the smoke coming from say a wood fire. This might have been a heating unit located in the guards van of the train. Currently operates continuously.
• Heating Hose ( named HeatingHoseFX) - represents the steam escaping from a steam pipe connection between wagons. By convention, it is suggested that this steam effect only be position on the start of each wagon. If it is placed on the rear of the wagon then the last car will have a steam leak which is probably not as realistic. Only operates when steam heating is operational on the train.
• Water Scoop ( named WaterScoopFX) - represents the water thrown up as the water scoop moves along the water trouygh or pan. By convention, it is suggested that this effect be positioned either side of the water scoop on each wagon. Only operates while the water scoop is in the down position, and train is on the water trough (currently only available in MG version).
• Tender Water Overflow ( named TenderWaterOverflowFX) - represents the water overflowing out of the tender or water tank when it is full, and the water scoop is left in the down position (currently only available in MG version).Only operates when water tank is full and scoop is left in down position.
• Bearing Hotbox ( named BearingHotboxFX) - represents the smoke generated in the bearing if it overheats (currently only available in MG version). Only operates whilst bearing temperature is above the warm temperature.
• Steam Brake Leaks ( named SteamBrakeFX) - represents the steam leaks associated with the operation of the steam brake. Turns on and off with the steam brake..

NB: If a visual effect is not defined in the SpecialEffects of the ENG or WAG file, then it will not be displayed in the simulation. If the effect is defined but all the direction parameters are set to zero the effect will not be displayed.

Note: Any of the wagon effects can be added to either a steam or diesel locomotive by adding the relevant visual effects into the wagon section of the respective ENG file.

The typical structure of the visual effects section for a wagon WAG files is as follows:

Effects (      
   SpecialEffects (
                  

   Effect Name (
                           Effect location
                           Effect direction
                           Effect nozzle width
                     )
           )
       )

Note: It is important to ensure that the opening and closing brackets for the effects section match up, otherwise errors maybe generated.

Effects Parameters Co-ordinates Description

Within each individual steam effect the following information is defined:

• Effect name - name defining which effect is defined (see above text for a list of the names).
• Effect location - location on the locomotive (given as an x, y, z offset in metres from the origin of the wagon shape).
• Effect direction - direction of emission (given as a normal x, y and z).
• Effect nozzle width - size of the exhaust nozzle in metres.

Location - Typically the origin point is in the centre of the locomotive, with the x, y and z axis describing a location referenced to this point. When looking to the front of the locomotive from the cab:

• X axis - to the right (+ve), or left (-ve)
• Y axis - in up (+ve) or down (-ve) direction.
• Z axis - to the front (+ve) or back (-ve) of the origin.

Direction - The direction of the effect (vector) is defined with the x, y and z axes using the same convention as the location stated above.

In most cases the effect is only required to show in one direction along the x, y or z axes. This is simple to define as in the following manner,

• X axis - to the right (+ve), or left (-ve)
• Y axis - in up (+ve) or down (-ve) direction.
• Z axis - to the front (+ve) or back (-ve) of the origin.

Any number greater or less than zero can be used for the single direction flow but it is obviously more convenient to use 1 or -1.

Angles can be created by visualising the diagram below, and allocating appropriate numbers to the y and z axes. A 45 deg. angle vector would have two of the axes with either a 1 or -1 value depending upon the direction required.

Calculate Effect Angle

Using the above convention of a Principal and Secondary Axis the following calculator will calculate the value required for the secondary axis. It is assumed that the Principal axis is set at a value of 1, and the angle between the principal axis and the desired direction is entered into the calculator.

Code Segments for Various Visual Effects Examples

Note: It is good practice to put notes into the ENG and WAG files to act as reminder for any assumptions made, or define which visual effect is being referenced. These notes can be made with comment statements as shown below:

Comment ( Injector - Left )

The steam effect examples on this page represents use of the steam configuration parameters described above to define different types of steam effects.

This type of code goes into the ENG file.

Typically the lines shown in red text are the only ones that would need to be changed to suit individual locomotives.

Useful References