In Transport Fever 2, bridge are constructed by UpdateFn, the game supplies bridgeutil.makeDefaultUpdateFn to generate an updateFn but you can ignore it and make you own bridge form.
params
The params are in the following structure:
{
pillarHeights = { ... },
pillarLength = ..,
pillarWidth = ..,
railingIntervals = {
{
hasPillar = { false, true },
lanes = {
{ offset = .., type = .. }
},
length = 26.934680938721
},
...
},
railingWidth = 4,
state = {
models = { ... }
}
}If you want to make your customized updateFn for bridge, the important information are pillarHeights, railingIntervals, railingWidth
The state.models table stores some mdl size information, which maybe useful
result
The result table requires two elements:
basic model elememt
A model element is expected in the following structure, we call it an M in the following text
pillarModels
pillarHeights describes the pillars of different heights requires by the game, so you need to give the answer in pillarModels for each height
pillarModels can be obtained by mapping pillarHeights subElements
for i = 1, #pillarHeights do
pillarModels[i] = fx(pillarHeights[i], railingIntervals, railingWidth)
endThe internal structure of each pillarModels[i] element is expected as a 2-order table
function fx(height, railingIntervals, railingWidth)
local result = fz(height, fy(...))
return result
endin which
fy(z, ...) returns a list of M arranged in horizontal direction, according to railingIntervals and railingWidth, z is the Z-axis displacement given by fz (only 1 M in case of a column pillar, or many in case of a wide pillar. nothing is case no pillar is needed)
fz(...) calculats the number and type of .mdl needed to stack the pillar in Z-axis and gives fy(...) needed information
Attention:
The heights given in pillarHeights are heights of the top of pillars
Assertion
#pillarModels == #pillarHeights
railingModels
railingModels describes the arrangement of railing models in forward direction, as X-axis, in each case, the railing many be divided into several segements
railingModels can be obtained by mapping railingIntervals subElements
for each segment, like the pillarModels, the railingModels[i] are expected to be a 2-order table
function fs(interval, railingWidth)
local result = fx(interval.length, fy(...))
return result
endin which
fy(x, offset, ...) returns a list of M arranged in horizontal direction, according to offset and railingWidth, x is the X-axis displacement given by fx, the offset is interval.lanes.offset, a list of each track/street arranged on Y-axis
fx(...) calculats the number and type of .mdl needed to arrange the railing X-axis and gives fy(...) needed information, based on the length given by the interval
The x = 0 point is aligned to the start of the track/street and the x = length point is the end of end.
Assertion
#railingModels == #railingHeights
Other requirements
If you are suffering from strange rotation of model on curves, try to set its pivot on x = 0, and the rest part of model on the positive x side
Attention:
For if the left and right railings are on the same mdl file, use X-aixs flipping rather than Z-aixs rotation by 180°, since the game will flip the normals of flipped models automatically.
Code example
(from Ventabren viaduc)
updateFn = function(params)
local result = {
railingModels = {},
pillarModels = {}
}
for i, height in ipairs(params.pillarHeights) do
local colHeight = height - 10.2
local nSeg = math.ceil(colHeight / 6)
local rs = {
{
{
id = "bridge/ventabren/pillar_top.mdl",
transf = {1, 0, 0, 0, 0, 1, 0, 0, 0, 0, 1, 0, 0, 0, height, 1}
}
}
}
for s = 1, nSeg do
table.insert(
rs,
{
{
id = "bridge/ventabren/pillar_btm.mdl",
transf = {1, 0, 0, 0, 0, 1, 0, 0, 0, 0, 1, 0, 0, 0, -10.2 - (s - 1) * 6 + height, 1}
}
}
)
end
table.insert(result.pillarModels, rs)
end
for i, interval in ipairs(params.railingIntervals) do
local nSeg = math.floor((interval.length) / 6)
if nSeg < 1 then nSeg = 1 end
local lSeg = interval.length / nSeg
local xScale = lSeg / 5.8
local minOffset = interval.lanes[1].offset
local maxOffset = interval.lanes[#interval.lanes].offset
local width = maxOffset - minOffset
local nPart = math.floor(width / 5)
local wPart = width / nPart
local yScale = wPart / 5
local set = function(n)
local partName = n == 1 and "start" or (n == nSeg and "end" or "start")
local x = (n - 1) * lSeg
local set = {
{
id = "bridge/ventabren/railing_" .. partName .. "_side.mdl",
transf = {xScale, 0, 0, 0, 0, 1, 0, 0, 0, 0, 1, 0, x, minOffset - 2, 0, 1}
},
{
id = "bridge/ventabren/railing_" .. partName .. "_side_2.mdl",
transf = {xScale, 0, 0, 0, 0, 1, 0, 0, 0, 0, 1, 0, x, maxOffset + 2, 0, 1}
}
}
for k = 1, nPart do
table.insert(set,
{
id = "bridge/ventabren/railing_" .. partName .. "_rep.mdl",
transf = {xScale, 0, 0, 0, 0, yScale, 0, 0, 0, 0, 1, 0, x, minOffset + (k - 1) * wPart, 0, 1}
}
)
end
return set
end
local rs = {}
for s = 1, nSeg do
table.insert(rs, set(s))
end
table.insert(result.railingModels, rs)
end
return result
end
