API ReferenceGE ExtensionseditortechroadArchitect

Road Architect - Junctions

Manages road junctions (intersections) in the Road Architect. Handles junction creation from road endpoints/midpoints, topology computation, lane connection mapping, and junction road generation.

Public Functions

Function	Signature	Description
`M.junctions`	``	Junctions data table
`M.addPedXJunction`	`(...)`	Adds a pedestrian crossing junction
`M.addCrossroads`	`(...)`	Adds a crossroads junction
`M.addTJunction`	`(...)`	Adds a T-junction
`M.addYJunction`	`(...)`	Adds a Y-junction
`M.addRoundaboutJunction`	`(...)`	Adds a roundabout junction
`M.addRuralUrbanTransJunction`	`(...)`	Adds a rural-urban transition junction
`M.addUrbanMergeJunction`	`(...)`	Adds an urban merge junction
`M.addUrbanSeparatorJunction`	`(...)`	Adds an urban separator junction
`M.addHighwayMergeJunction`	`(...)`	Adds a highway merge junction
`M.addHighwayUrbanTransJunction`	`(...)`	Adds a highway-urban transition junction
`M.addHighwaySeparatorJunction`	`(...)`	Adds a highway separator junction
`M.addShoulderFadeJunction`	`(...)`	Adds a shoulder fade junction
`M.addHighwaySlipJunction`	`(...)`	Adds a highway slip junction
`M.updateJunctionAfterChange`	`(...)`	Updates junction after modification
`M.removeJunction`	`(...)`	Removes a junction
`M.clearAllJunctions`	`()`	Clears all junctions
`M.getJunctionCentroid`	`(...)`	Gets the centroid of a junction
`M.computeInitRot`	`(...)`	Computes initial rotation for junction
`M.translateJunction`	`(...)`	Translates a junction
`M.rotateJunction`	`(...)`	Rotates a junction
`M.rotateJunctionQuat`	`(...)`	Rotates a junction by quaternion
`M.goToJunction`	`(...)`	Navigates camera to a junction
`M.setAllMeshProperty`	`(...)`	Sets mesh property on all junction meshes
`M.updateJunctionsAfterRoadRemove`	`(...)`	Updates junctions after road removal
`M.updateJunctionCondition`	`(...)`	Updates junction condition data
`M.finaliseJunction`	`(...)`	Finalises a junction
`M.copyJunction`	`(...)`	Copies a junction
`M.serialiseJct`	`(...)`	Serializes a junction
`M.deserialiseJct`	`(...)`	Deserializes a junction
`M.saveJunction`	`(...)`	Saves a junction
`M.loadJunction`	`(...)`	Loads a junction
`M.chopRoadsToSphere`	`(...)`	Chops roads to a sphere region
`M.createAutoJctOverlays`	`(...)`	Creates automatic junction overlays
`M.importRoadsFromLSystem`	`(...)`	Imports roads from L-system

Example: Junction Workflow

local junctions = require('editor/tech/roadArchitect/junctions')

-- Find junction candidates near selected road endpoint
local candidates = junctions.getJunctionCandidates(roads, map, selRoadIdx, selNodeIdx)

-- Check candidate type
for _, c in ipairs(candidates) do
  if junctions.isEnd2End(c) then
    -- Two road endpoints meeting
  elseif junctions.isEnd2Mid(c) then
    -- One road endpoint meeting another's midpoint (T-junction)
  end
end

-- Create a junction from candidates
junctions.createJunction(roads, map, candidates)

-- After editing a connected road, update the junction
junctions.updateJunction(jIdx, allJunctions, roads, map)

-- Junction internals:
-- 1. Topology: maps which lanes connect across the intersection
-- 2. Junction roads: auto-generated short road segments connecting lanes
-- 3. These roads are marked isJctRoad = true (hidden in normal editing)

-- Remove a junction (also removes generated roads)
junctions.removeJunction(jIdx, allJunctions, roads, map)

Notes

Supports T-junctions (end-to-mid) and cross/Y junctions (end-to-end)
Junction roads are auto-generated with matching lane profiles
Lane connections computed from road heading and lane ordering

Functions

`addPedXJunction(isNew)`

Adds ped x junction.

isNew (any)

`addCrossroads(isNew)`

Adds crossroads.

isNew (any)

`addTJunction(isNew)`

Adds t junction.

isNew (any)

`addYJunction(isNew)`

Adds y junction.

isNew (any)

`addRoundaboutJunction(isNew)`

Adds roundabout junction.

isNew (any)

`addRuralUrbanTransJunction(isNew)`

Adds rural urban trans junction.

isNew (any)

`addUrbanMergeJunction(isNew)`

Adds urban merge junction.

isNew (any)

`addUrbanSeparatorJunction(isNew)`

Adds urban separator junction.

isNew (any)

`addHighwayMergeJunction(isNew)`

Adds highway merge junction.

isNew (any)

`addHighwayUrbanTransJunction(isNew)`

Adds highway urban trans junction.

isNew (any)

`addHighwaySeparatorJunction(isNew)`

Adds highway separator junction.

isNew (any)

`addShoulderFadeJunction(isNew)`

Adds shoulder fade junction.

isNew (any)

`addHighwaySlipJunction(isNew)`

Adds highway slip junction.

isNew (any)

`updateJunctionAfterChange(jIdx)`

Updates junction after change.

jIdx (any)

`clearAllJunctions()`

Clears all junctions.

`getJunctionCentroid(jIdx)`

Returns the junction centroid.

jIdx (any)

Returns: n1 + (n2 - n1) * 0.5

`computeInitRot(jIdx)`

Computes init rot.

jIdx (any)

Returns: util.getRotationBetweenVecs(xAxis, v1)

`translateJunction(jIdx, offset)`

Handles translate junction.

jIdx (any)
offset (vec3|number)

`rotateJunction(jIdx, cen, theta)`

Handles rotate junction.

jIdx (any)
cen (any)
theta (any)

`rotateJunctionQuat(jIdx, cen, q)`

Handles rotate junction quat.

jIdx (any)
cen (any)
q (any)

`goToJunction(jIdx)`

Handles go to junction.

jIdx (any)

`setAllMeshProperty(jIdx)`

Sets the all mesh property.

jIdx (any)

`updateJunctionsAfterRoadRemove()`

Updates junctions after road remove.

`updateJunctionCondition(jct)`

Updates junction condition.

jct (any)

`finaliseJunction(jIdx)`

Handles finalise junction.

jIdx (any)

`copyJunction(jct)`

Handles copy junction.

jct (any)

Returns: table

`serialiseJct(jct)`

Handles serialise jct.

jct (any)

Returns: table

`deserialiseJct(jSer)`

Handles deserialise jct.

jSer (any)

Returns: table

`saveJunction(jIdx)`

Saves junction.

jIdx (any)

`loadJunction()`

Loads junction.

`chopRoadsToSphere(jNodes, jCen, jRad)`

Handles chop roads to sphere.

jNodes (any)
jCen (any)
jRad (any)

`createAutoJctOverlays(jNodes, laneWidth, jctCen)`

Creates auto jct overlays.

jNodes (any)
laneWidth (any)
jctCen (any)

`importRoadsFromLSystem(roadNetwork, intersections, DOI, margin, doTerraform)`

Imports roads from l system.

roadNetwork (any)
intersections (any)
DOI (any)
margin (any)
doTerraform (any)

Returns: self

Functions

`addPedXJunction(isNew)`

Adds ped x junction.

isNew (any)

`addCrossroads(isNew)`

Adds crossroads.

isNew (any)

`addTJunction(isNew)`

Adds t junction.

isNew (any)

`addYJunction(isNew)`

Adds y junction.

isNew (any)

`addRoundaboutJunction(isNew)`

Adds roundabout junction.

isNew (any)

`addRuralUrbanTransJunction(isNew)`

Adds rural urban trans junction.

isNew (any)

`addUrbanMergeJunction(isNew)`

Adds urban merge junction.

isNew (any)

`addUrbanSeparatorJunction(isNew)`

Adds urban separator junction.

isNew (any)

`addHighwayMergeJunction(isNew)`

Adds highway merge junction.

isNew (any)

`addHighwayUrbanTransJunction(isNew)`

Adds highway urban trans junction.

isNew (any)

`addHighwaySeparatorJunction(isNew)`

Adds highway separator junction.

isNew (any)

`addShoulderFadeJunction(isNew)`

Adds shoulder fade junction.

isNew (any)

`addHighwaySlipJunction(isNew)`

Adds highway slip junction.

isNew (any)

`updateJunctionAfterChange(jIdx)`

Updates junction after change.

jIdx (any)

`clearAllJunctions()`

Clears all junctions.

`getJunctionCentroid(jIdx)`

Returns the junction centroid.

jIdx (any)

Returns: n1 + (n2 - n1) * 0.5

`computeInitRot(jIdx)`

Computes init rot.

jIdx (any)

Returns: util.getRotationBetweenVecs(xAxis, v1)

`translateJunction(jIdx, offset)`

Handles translate junction.

jIdx (any)
offset (vec3|number)

`rotateJunction(jIdx, cen, theta)`

Handles rotate junction.

jIdx (any)
cen (any)
theta (any)

`rotateJunctionQuat(jIdx, cen, q)`

Handles rotate junction quat.

jIdx (any)
cen (any)
q (any)

`goToJunction(jIdx)`

Handles go to junction.

jIdx (any)

`setAllMeshProperty(jIdx)`

Sets the all mesh property.

jIdx (any)

`updateJunctionsAfterRoadRemove()`

Updates junctions after road remove.

`updateJunctionCondition(jct)`

Updates junction condition.

jct (any)

`finaliseJunction(jIdx)`

Handles finalise junction.

jIdx (any)

`copyJunction(jct)`

Handles copy junction.

jct (any)

Returns: table

`serialiseJct(jct)`

Handles serialise jct.

jct (any)

Returns: table

`deserialiseJct(jSer)`

Handles deserialise jct.

jSer (any)

Returns: table

`saveJunction(jIdx)`

Saves junction.

jIdx (any)

`loadJunction()`

Loads junction.

`chopRoadsToSphere(jNodes, jCen, jRad)`

Handles chop roads to sphere.

jNodes (any)
jCen (any)
jRad (any)

`createAutoJctOverlays(jNodes, laneWidth, jctCen)`

Creates auto jct overlays.

jNodes (any)
laneWidth (any)
jctCen (any)

`importRoadsFromLSystem(roadNetwork, intersections, DOI, margin, doTerraform)`

Imports roads from l system.

roadNetwork (any)
intersections (any)
DOI (any)
margin (any)
doTerraform (any)

Returns: self

Public Functions

Function	Signature	Description
`M.junctions`	``	Junctions data table
`M.addPedXJunction`	`(...)`	Adds a pedestrian crossing junction
`M.addCrossroads`	`(...)`	Adds a crossroads junction
`M.addTJunction`	`(...)`	Adds a T-junction
`M.addYJunction`	`(...)`	Adds a Y-junction
`M.addRoundaboutJunction`	`(...)`	Adds a roundabout junction
`M.addRuralUrbanTransJunction`	`(...)`	Adds a rural-urban transition junction
`M.addUrbanMergeJunction`	`(...)`	Adds an urban merge junction
`M.addUrbanSeparatorJunction`	`(...)`	Adds an urban separator junction
`M.addHighwayMergeJunction`	`(...)`	Adds a highway merge junction
`M.addHighwayUrbanTransJunction`	`(...)`	Adds a highway-urban transition junction
`M.addHighwaySeparatorJunction`	`(...)`	Adds a highway separator junction
`M.addShoulderFadeJunction`	`(...)`	Adds a shoulder fade junction
`M.addHighwaySlipJunction`	`(...)`	Adds a highway slip junction
`M.updateJunctionAfterChange`	`(...)`	Updates junction after modification
`M.removeJunction`	`(...)`	Removes a junction
`M.clearAllJunctions`	`()`	Clears all junctions
`M.getJunctionCentroid`	`(...)`	Gets the centroid of a junction
`M.computeInitRot`	`(...)`	Computes initial rotation for junction
`M.translateJunction`	`(...)`	Translates a junction
`M.rotateJunction`	`(...)`	Rotates a junction
`M.rotateJunctionQuat`	`(...)`	Rotates a junction by quaternion
`M.goToJunction`	`(...)`	Navigates camera to a junction
`M.setAllMeshProperty`	`(...)`	Sets mesh property on all junction meshes
`M.updateJunctionsAfterRoadRemove`	`(...)`	Updates junctions after road removal
`M.updateJunctionCondition`	`(...)`	Updates junction condition data
`M.finaliseJunction`	`(...)`	Finalises a junction
`M.copyJunction`	`(...)`	Copies a junction
`M.serialiseJct`	`(...)`	Serializes a junction
`M.deserialiseJct`	`(...)`	Deserializes a junction
`M.saveJunction`	`(...)`	Saves a junction
`M.loadJunction`	`(...)`	Loads a junction
`M.chopRoadsToSphere`	`(...)`	Chops roads to a sphere region
`M.createAutoJctOverlays`	`(...)`	Creates automatic junction overlays
`M.importRoadsFromLSystem`	`(...)`	Imports roads from L-system

Example: Junction Workflow

local junctions = require('editor/tech/roadArchitect/junctions')

-- Find junction candidates near selected road endpoint
local candidates = junctions.getJunctionCandidates(roads, map, selRoadIdx, selNodeIdx)

-- Check candidate type
for _, c in ipairs(candidates) do
  if junctions.isEnd2End(c) then
    -- Two road endpoints meeting
  elseif junctions.isEnd2Mid(c) then
    -- One road endpoint meeting another's midpoint (T-junction)
  end
end

-- Create a junction from candidates
junctions.createJunction(roads, map, candidates)

-- After editing a connected road, update the junction
junctions.updateJunction(jIdx, allJunctions, roads, map)

-- Junction internals:
-- 1. Topology: maps which lanes connect across the intersection
-- 2. Junction roads: auto-generated short road segments connecting lanes
-- 3. These roads are marked isJctRoad = true (hidden in normal editing)

-- Remove a junction (also removes generated roads)
junctions.removeJunction(jIdx, allJunctions, roads, map)