New TransF Matrix - What is it?

Well, it's not exactly new. This is a hangover from Train Fever and TpF1. "Discovered" by Killakanz, this matrix is a far more readable version of the one used in the game and generated by the model editor.

This matrix is unique for describing angles and degrees of rotation in simple notation. And is formatted like this:

transf = transf.scaleRotZYXTransl(
    vec3.new(1.0,1.0,1.0),
    transf.degToRad( 0.0, 0.0, 0.0),
    vec3.new( 0.0, 0.0, 0.0),
    ),

  vec3.new(1.0,1.0,1.0),

transf.degToRad( 0.0, 0.0, 0.0)

vec3.new( 0.0, 0.0, 0.0),

Animations for steam locos using VehicleUtil

To use the vehicleutil animations, and the classic keyframes, first define these variables in your .MDL file.

local vec2 = require "vec2"
local vec3 = require "vec3"
local transf = require "transf"
local vehicleutil = require "vehicleutil"

Lets cover the 3 basic animation types

Pistons

drive = vehicleutil.makePistonAnim(vec2.new(0,0), vec2.new(0,0), vec2.new(0,0))

Connecting Rod (Crank rod)

drive = vehicleutil.makeConnectingRodAnim(vec2.new(0,0), vec2.new(0,0), vec2.new(0,0))

Coupling Rod

drive = vehicleutil.makeCouplingRodAnim(vec2.new(0,0), vec2.new(0,0), vec2.new(0,0))

How to get the correct values for proper animation

We will take the most complex, connecting rod, and take it apart to see what each bit does

drive

The animation trigger. This means it animates when moving in relation to the speed of the vehicle.

= vehicleutil.

Uses the vehicleutil function

makeCouplingRodAnim

Defines the kind of animation

(vec2.new(0,0),

This first vec2 defines the animation duration. (vec2.new(0,WHEEL_AXLE_HEIGHT)

(vec2.new(0,0),

The second vec2 defines the animation extent. How far your rods move. (vec2.new(0,ROD_HEIGHT)

(vec2.new(0,0),

The last vec2 defines the motion of the connecting rod and piston animations.
(vec2.new(ROD_LENGTH,ROD_HEIGHT)

This will get you all you need for locomotives without outside valve gear

If you have Walschearts Valve Gear

There are 2 more tricks for getting smooth movement of the rods before we go to keyframes.

Make a wheel mesh with the offset crank on the wheel itself, or make the offset crank have its origin the same as a wheel, and define it as an axle. This will ensure smooth rotation. 

The return rod

There is a trick you can do with the return rod to make it work like the other animations and not need keyframes. Make sure to origin the return rod at the end that connects to the offset crank.

drive = vehicleutil.makeConnectingRodAnim
(vec2.new(0,AXLE_HEIGHT),
 vec2.new(ROD_OFFSET_X,AXLE_HEIGHT),
 vec2.new(ROD_LENGTH,AXLE_HEIGHT))

Local declares for VehicleUtil compatibility

local transf = require "transf"
local vec2 = require "vec2"
local vec3 = require "vec3"
local vehicleutil = require "vehicleutil"

.mdl file module

{
	materials = { "vehicle/train/material.mtl", },
	mesh = "vehicle/train/mesh_file.msh",
	transf = {	1, 0, 0, 0, 0, 1, 0, 0, 0, 0, 1, 0, 0, 0, 0, 1, },
},

Group file name

groupFileName = "vehicle/train/model_menu.mdl",

vehicle crew template

{
	animation = "idle",
	crew = true,
	forward = true,
	group = 1,
	transf = { 1, 0, -0, 0, 0, 1, 0, 0, 0, 0, 1, 0, -3, -0.5, 1.5, 1, },
},

Engines and metadata template for steam loco (50mph, 1000hp, 50000lb/f)

engines = {
		{
			power = 745.71,
			tractiveEffort = 222.22,
			type = "STEAM",
		},
	},
	soundSet = {
		name = "soundset_name",
	},
	topSpeed = 22.35,
	weight = 105,
},

Particle emissions template for steam loco (taken from Big Bertha locomotive)

particleSystem = {
	emitters = {
		{
			position = {4.2, .0, 3.8589},
			velocity = { .0, .0, 8.0 },
			color = { .2, .2, .2 },
			frequency = 50,
			lifeTime = 20.0,
			size01 = { 1.2, 16.0 },
			child = 1
		},
		{
			position = {-3, .0, 3.7},
			velocity = { .0, .0, 5.0 },
			color = { .9, .9, .9 },
			frequency = 70,
			lifeTime = 5.0,
			size01 = { .2, 3.0 },
			child = 1
		},
		{
			position = { 4.2, 1.283, 1.5 },
			velocity = { .0, 3.0, 0.0 },
			color = { .9, .9, .9 },
			frequency = 9,
			lifeTime = 2.5,
			size01 = { .4, 5.0 },
			child = 1
		},
		{
			position = { 4.2, -1.283, 1.5 },
			velocity = { .0, -3.0, 0.0 },
			color = { .9, .9, .9 },
			frequency = 9,
			lifeTime = 2.5,
			size01 = { .4, 5.0 },
			child = 1
		},
	},
},