tokyo-wangan-racing/tools/diag_nosecue2.luau

--[[
	diag_nosecue2.luau -- settle which is lying on hatch_junk / hyper_x: the
	wheel LABELS, or the shell MESH itself.

	Background: diag_shelllabels.luau showed those two shells label their F
	axle toward +Z while rx7_fc / silv_s15 / gtr_r34 label F toward -Z. That
	matches the reported symptom exactly, but it does NOT say which side is
	wrong -- either the labels are swapped, or the whole mesh is authored
	facing the other way and the labels are honest.

	So: gather cues that are INDEPENDENT of the wheel names, from the shell's
	own parts. Every cue is read off part names/positions in the shell's local
	frame; none is derived from a constant, and each can come out either way.

	  headlights  -- sit at the NOSE
	  taillights  -- sit at the TAIL
	  *front* / *rear* named parts (bumpers, grille) -- self-describing
	  seat        -- a VehicleSeat/Seat inside the shell looks FORWARD

	Interpretation:
	  * cues agree with labels  -> the MESH is rotated; labels are honest
	  * cues oppose the labels  -> the LABELS are swapped; mesh is fine
	A shell where cues themselves disagree is reported as INCONCLUSIVE rather
	than being forced into a verdict.
]]

local RS = game:GetService("ReplicatedStorage")
local SSS = game:GetService("ServerScriptService")
local SS = game:GetService("ServerStorage")

local TARGETS = { rx7_fc = true, hatch_junk = true, silv_s15 = true, gtr_r34 = true, hyper_x = true }

local out = {}
local function log(s)
	table.insert(out, s)
end

-- Collect the five target shells wherever they live.
local shells = {}
for _, root in ipairs({ RS, SSS, SS, workspace }) do
	for _, d in ipairs(root:GetDescendants()) do
		if d:IsA("Model") and TARGETS[d.Name] and d:FindFirstChild("Wheels") and not shells[d.Name] then
			shells[d.Name] = d
		end
	end
end

-- Mean local Z of every part whose lowercased name matches a pattern.
local function meanZ(shell, pivotInv, patterns)
	local sum, n = 0, 0
	for _, d in ipairs(shell:GetDescendants()) do
		if d:IsA("BasePart") then
			local nm = d.Name:lower()
			for _, pat in ipairs(patterns) do
				if nm:find(pat, 1, true) then
					sum += (pivotInv * d.Position).Z
					n += 1
					break
				end
			end
		end
	end
	if n == 0 then
		return nil, 0
	end
	return sum / n, n
end

local order = { "rx7_fc", "silv_s15", "gtr_r34", "hatch_junk", "hyper_x" }

log(
	string.format(
		"%-11s %-14s %-14s %-14s %-14s %s",
		"shell",
		"labelF.Z",
		"headlight.Z",
		"taillight.Z",
		"seatFwd.Z",
		"verdict"
	)
)
log(string.rep("-", 104))

local seen = 0
for _, name in ipairs(order) do
	local shell = shells[name]
	if not shell then
		log(string.format("%-11s NOT FOUND", name))
		continue
	end
	seen += 1
	local pivotInv = shell:GetPivot():Inverse()

	-- Wheel-label cue: sign of (F centroid - R centroid).Z
	local wheels = shell:FindFirstChild("Wheels")
	local fSum, fN, rSum, rN = 0, 0, 0, 0
	for _, w in ipairs(wheels:GetChildren()) do
		local sum, n = Vector3.zero, 0
		if w:IsA("BasePart") then
			sum, n = w.Position, 1
		end
		for _, d in ipairs(w:GetDescendants()) do
			if d:IsA("BasePart") then
				sum, n = sum + d.Position, n + 1
			end
		end
		if n > 0 then
			local z = (pivotInv * (sum / n)).Z
			local head = w.Name:sub(1, 1):upper()
			if head == "F" then
				fSum, fN = fSum + z, fN + 1
			elseif head == "R" then
				rSum, rN = rSum + z, rN + 1
			end
		end
	end
	local labelZ = (fN > 0 and rN > 0) and ((fSum / fN) - (rSum / rN)) or nil

	local headZ, headN = meanZ(shell, pivotInv, { "headlight", "headlamp", "grille", "grill" })
	local tailZ, tailN = meanZ(shell, pivotInv, { "taillight", "taillamp", "tailight", "brakelight" })

	-- Seat cue: a seat's LookVector, expressed in the SHELL's frame.
	local seatZ = nil
	for _, d in ipairs(shell:GetDescendants()) do
		if d:IsA("VehicleSeat") or d:IsA("Seat") then
			-- Rotate (not translate) the seat's world look into shell-local axes.
			seatZ = (shell:GetPivot():Inverse() * (d.CFrame.LookVector + shell:GetPivot().Position)).Z
			break
		end
	end

	-- Each cue votes for which local Z direction is the NOSE.
	-- Convention target: nose should be at -Z.
	local votes = {}
	if headZ then
		votes[#votes + 1] = (headZ < 0) and -1 or 1
	end
	if tailZ then
		votes[#votes + 1] = (tailZ < 0) and 1 or -1
	end -- tail opposes nose
	if seatZ then
		votes[#votes + 1] = (seatZ < 0) and -1 or 1
	end

	local noseSign = nil
	if #votes > 0 then
		local s = 0
		for _, v in ipairs(votes) do
			s += v
		end
		if s > 0 then
			noseSign = 1
		elseif s < 0 then
			noseSign = -1
		end
	end

	local verdict
	if not labelZ then
		verdict = "no F/R labels"
	elseif #votes == 0 then
		verdict = "NO INDEPENDENT CUE (no lights/seat found)"
	elseif noseSign == nil then
		verdict = "INCONCLUSIVE (cues split)"
	else
		local labelSign = (labelZ < 0) and -1 or 1
		if labelSign == noseSign then
			verdict = (noseSign < 0) and "consistent, nose -Z (fine)" or "LABELS HONEST -> MESH is rotated 180"
		else
			verdict = "LABELS SWAPPED -> mesh is fine"
		end
	end

	local function fmt(v, n)
		return v and string.format("%+.1f(%d)", v, n or 0) or "--"
	end
	log(
		string.format(
			"%-11s %-14s %-14s %-14s %-14s %s",
			name,
			labelZ and string.format("%+.1f", labelZ) or "--",
			fmt(headZ, headN),
			fmt(tailZ, tailN),
			seatZ and string.format("%+.2f", seatZ) or "--",
			verdict
		)
	)
end

log("")
if seen == 0 then
	log(">>> NOTHING INSPECTED -- this is a FAILURE, not a pass.")
else
	log(string.format(">>> inspected %d/5 shells", seen))
	log("    labelF.Z    = (F centroid - R centroid).Z; negative means labels put F toward -Z")
	log("    headlight.Z = mean local Z of headlight/grille parts (count); nose should be -Z")
	log("    seatFwd.Z   = seat LookVector Z in shell frame; negative = seat faces -Z")
end

return table.concat(out, "\n")