Help with T-Junctions!

[jtrhooms]

I’m Building a Dungeon Generator - Help with T-Junctions!

I’m creating a cool algorithm that builds dungeons! I’ve got the basic layout and paths figured out using pathfinding algorithms like A*. Now I’m stuck on a tricky part: hallways with two paths.

Imagine a hallway that connects two different corridors in the dungeon. These corridors could be coming from any direction (north, south, east, west). My problem is figuring out which way this hallway should face to smoothly connect both paths and make sense for the player’s exploration.

What I already have

local hallwayType = function(d1:Vector3, d2:Vector3, NodesEnteringCurrent:table)	
	local LeftVector = Vector3.new(-1,0,0) 
	local RightVector = Vector3.new(1,0,0)

	local BackVector = Vector3.new(0,0,1) 
	local LookVector = Vector3.new(0,0,-1) 
		
	--print(d1, d2)
	
	if #NodesEnteringCurrent > 1 then
		if(d2 == nil and (d1 == LookVector or d1 == BackVector)) or (d1 == d2) then
			if (NodesEnteringCurrent[1] == LookVector and NodesEnteringCurrent[2] == BackVector) or (NodesEnteringCurrent[1] == BackVector and NodesEnteringCurrent[2] == LookVector) then
				return "Front"
			end

			if (NodesEnteringCurrent[1] == RightVector and NodesEnteringCurrent[2] == LeftVector) or (NodesEnteringCurrent[1] == LeftVector and NodesEnteringCurrent[2] == RightVector) then
				return "Front"
			end
		end
		
		return "Junction"
	else
		if(d2 == nil and (d1 == LookVector or d1 == BackVector)) or (d1 == d2) then
			return "Front"
		elseif (d1 == RightVector and d2 == LookVector) or (d1 == LeftVector and d2 == BackVector) or (d1 == LookVector and d2 == LeftVector) or (d1 == BackVector and d2 == RightVector) then
			return "Left"
		elseif (d1 == LookVector and d2 == RightVector) or (d1 == BackVector and d2 == LeftVector) or (d1 == RightVector and d2 == BackVector) or (d1 == LeftVector and d2 == LookVector) then
			return "Right"
		end
	end
	
	return nil
end


local createHallWays = function(path:table, totalPathNodes:table, nodePlaced:table)
	local startNode, EndNode
	
	for i, Node:Node in pairs(path) do
		if nodePlaced[Node.Position] or Node.Type ~= "Air" then continue end
		nodePlaced[Node.Position] = true
		local direction
		local d1, d2
		local HWType
		
		if not path[i-1] or not path[i+1] then 
			HWType = "Front"
		else
			d1 = (path[(i+1)].Position - Node.Position).Unit
			d2 = (Node.Position - path[(i-1)].Position).Unit
			HWType = hallwayType(d1, d2, totalPathNodes[Node.Position])
		end
		
		if not HWType then return false end
		
		local Lookat
		local cube

		if totalPathNodes[Node.Position] and #totalPathNodes[Node.Position] > 1 and HWType ~= "Front" then
			print(totalPathNodes[Node.Position])
			if #totalPathNodes[Node.Position] >= 3 then
				cube = RepStorage.HallWays.Intersection:Clone()
			elseif #totalPathNodes[Node.Position] == 2 then
				if path[i+1].Type == "Air" then
					--if direction == "Left" then
					--	cube = RepStorage.HallWays.LeftJunction:Clone()
					--elseif direction == "Right" then
					--	cube = RepStorage.HallWays.RightJunction:Clone()
					--end
					Lookat = path[i-1].Position
				else
					Lookat = path[i+1].Position
				end
				
				cube = RepStorage.HallWays.Junction:Clone()
			end
		else
			if HWType == "Front" then
				cube = RepStorage.HallWays.HallWay1:Clone()
			elseif HWType == "Left" then
				cube = RepStorage.HallWays.LeftHallWay:Clone()
			elseif HWType == "Right" then
				cube = RepStorage.HallWays.RightHallWay:Clone()
			end
			Lookat = path[i-1].Position
		end
		
		if not cube then print(HWType) warn("No Hallway Found") return end
		
		if not startNode then startNode = cube else EndNode = cube end
		--cube.Name = "Hallway "..i
		--cube.Size = Vector3.new(12,12,12)
		--cube.Position = Node.Position
		cube:PivotTo(CFrame.new(Node.Position, Lookat))
		--cube.Anchored = true
		--cube.Material = Enum.Material.SmoothPlastic
		--cube.CanCollide = false
		--cube.BrickColor = BrickColor.new("Dark stone grey")
		cube.Parent = workspace.Dungeon.HallWays
		CreateDoor(startNode)
		if EndNode then CreateDoor(EndNode) end
		wait()
	end	
	
	--print(startNode, EndNode)
end

[jtrhooms]

So I ended up solving it, by tracking every direction going in and out from the Node that the Junction will occupy, Since there are only 3 connections on a T junction, I just track the direction from the T-Junction Node to the nodes that will be connecting it.