"Bogeys" container

Latest revision as of 09:19, 7 May 2019

The bogeys container is a list of bogey subcontainers and is used by KIND Traincar assets. Each bogey subcontainer has a unique tag name and these tag names are matched with bogie attachments in the traincar mesh. These are a.bog0, a.bog1, etc.

[edit] Supported Tags

Each bogey container supports the following tags. Each tag is shown here with its default value.

 bogey              <KUID:0:0>
 reversed           0
 rotation-permitted 1
 sideplay-permitted 0

[edit] bogey

Type: Asset KUID

Desc: Specifies the bogie asset to use at the attachment point.

[edit] reversed

Type: Boolean

Desc: Reverses the animation direction. Used when the bogie attachment point in the traincar asset has been rotated 180 degrees around the Z axis. 1 is reversed. 0 is not reversed and the default value.

[edit] rotation-permitted

Type: Boolean

Desc: Allows the bogey to rotate itself in the Z axis to align with track direction. If 1 (default) then the bogey will rotate and if 0 then the bogey will not rotate. Using a zero value can be useful when the wheels being represented are fixed to the frame of the vehicle, and are not mounted on a rotating bogey.

[edit] sideplay-permitted

Type: Boolean

Desc: Allows the bogie asset to move sideways to follow the track rather than remaining fixed at its attachment point. 0 (default) is no sideplay. 1 allows sideplay.

[edit] Examples

[edit] Example 1

A Tri-Bo locomotive where the centre bogie slides from side to side can be represented like this:

bogeys {
  0 {
    reversed           0
    bogey              <KUID2:xxxxx:yyyyy:zzz>
  }
  1 {
    reversed           1
    bogey              <KUID2:xxxxx:yyyyy:zzz>
   }
  2 {
    reversed           0
    sideplay-permitted 1
    bogey              <KUID2:xxxxx:yyyyy:zzz>
  }
}

a.bog0 and a.bog1 are used for the two end bogies, and will locate the vehicle on the track. But the bogie attached at a.bog2 in the middle will now follow the track through curves rather than stay firmly riveted on the underframe with it's wheels dangling in mid air.

[edit] Example 2

This is a loco with central power bogies, and outer bogies to help traverse curves. The PRR GG1 (wheel pattern 2-co-co-2) is of this type. This can now be represented as follows:

bogeys {
  0 {
    reversed           0
    bogey              <KUID2:xxxxx:yyyyy:zzz>
  }
  1 {
    reversed           1
    bogey              <KUID2:xxxxx:yyyyy:zzz>
  }
  2 {
    reversed           0
    sideplay-permitted 1
    bogey              <KUID2:xxxxx:yyyyy:zzz>
  }
  3 {
    reversed           1
    sideplay-permitted 1
    bogey              <KUID2:xxxxx:yyyyy:zzz>
  }
}

a.bog0 and a.bog1 are used for the main power bogies to locate the vehicle correctly on the track. a.bog2 and a.bog3 are used for the leading and trailing unpowered bogies. These are permitted sideplay so they follow the track.

[edit] Example 3

A two axle rigid frame vehicle can be represented as follows:

bogeys {
  0 {
    reversed           0
    rotation-permitted 0
    bogey              <KUID2:xxxxx:yyyyy:zzz>
  }
  1 {
    reversed           1
    rotation-permitted 0
    bogey              <KUID2:xxxxx:yyyyy:zzz>
  }
}

In this case, each bogie would be a single axle. The location of the attachment point will specify how the vehicle is aligned when on a curve, so should be placed at the location of the axle in the 'y' direction.

[edit] Example 4

An interesting case might be a three axle rigid frame vehicle - with sideplay (but no rotation!) on the centre axle. This might be represented as follows:

bogeys {
  0 {
    reversed           0
    rotation-permitted 0
    bogey              <KUID2:xxxxx:yyyyy:zzz>
  }
  1 {
    reversed           0
    rotation-permitted 0
    bogey              <KUID2:xxxxx:yyyyy:zzz>
  }
  2 {
    reversed           0
    rotation-permitted 0
    sideplay-permitted 1
    bogey              <KUID2:xxxxx:yyyyy:zzz>
  }
}

[edit] Example 5

These tags are useful for steam locos too. Consider the pacific '4-6-2' wheel pattern. Looking from the front (a.limfront) end through to the back (a.limback), one way to arrange the bogie attachment points to get the required behaviour is:

a.bog2 - front bogie (the '4' in '4-6-2'). For best results, the attachment point should be the centre of the wheelbase. Use 'sideplay-permitted 1' on this bogie.

a.bog0 - drive bogie (the '6' in '4-6-2'). The attachment point should be circa where the front axle is. Move it back a bit if you have a lot of axles (e.g. 5 or more) in the drive bogie. Configure this one with 'sideplay-permitted 0' and 'rotation-permitted 0' - you don't want it moving around on curves at all! (With 'rotation-permitted 0' there is now no need to locate it at 0,0,0 to stop it rotating).

a.bog1 - an invisible bogie in line with the rear axle of the drive bogie. Move slightly forward if your drive bogie is large (e.g. 5 axles or more). This will make the locomotive body follow the track properly.

a.bog3 - trailing pony truck (the '2' in '4-6-2'). The attachment point should be in line with axle. Use 'sideplay-permitted 1' as with the front bogie.

This will produce the correct behaviour both from the locomotive body and the various bogies.

Using these parameters should mean that even very flexible locos (e.g. a Mallet or Garratt) can be built in a much more realistic manner, and with fewer separate pieces that need assembly in Surveyor.

[edit] Random debugging hint

Q: "But I set this feature, and when I go round a corner, my bogie now floats off in some other direction that I wasn't expecting! What is wrong?"

A: Have you by any chance rotated the attachment point by 180 degrees in your 3D editor to get the bogie to appear the other way round, but not set "reversed 1" in the config container for that bogie? These two things together can cause the effect you are seeing. You should also be able to spot this case because your wheels will be rotating the wrong way...