tokyo-wangan-racing/tools/probe_floating.luau

-- FLOATING SCENERY PROBE.
--
-- The wide captures show grey slabs/towers hanging in the sky with nothing
-- under them. No existing probe catches this: the clip probe only asks
-- "does road intersect building", which is 0 and correct. Floating geometry
-- is the opposite failure -- parts that touch NOTHING at all.
--
-- Metric: for each candidate scenery part, raycast straight DOWN from its
-- underside and report the distance to the first thing hit. A part sitting
-- on ground/deck returns ~0. A floating part returns a large number or nil
-- (nothing beneath it at all).
--
-- CONTROL: the same ray cast from a part known to be seated (a Road part)
-- must return a small distance. If the control comes back nil/huge the
-- raycast itself is broken and every "floating" result is meaningless --
-- the silent-zero trap that produced two phantom defects earlier.

local ws = game:GetService("Workspace")
local map = ws:FindFirstChild("Map")
if not map then
	return "NO MAP"
end

local candidates, roads = {}, {}
for _, d in ipairs(map:GetDescendants()) do
	if d:IsA("BasePart") then
		local nm = d.Name
		if nm:sub(1, 5) == "Road_" then
			table.insert(roads, d)
		elseif
			nm:find("Building")
			or nm:find("Tower")
			or nm:find("Skyline")
			or nm:find("Block")
			or nm:find("Slab")
			or nm:find("Distant")
		then
			table.insert(candidates, d)
		end
	end
end

local params = RaycastParams.new()
params.FilterType = Enum.RaycastFilterType.Exclude

-- distance from a part's underside straight down to the first hit
local function dropDist(p)
	params.FilterDescendantsInstances = { p }
	local origin = p.Position - Vector3.new(0, p.Size.Y / 2 + 1, 0)
	local res = ws:Raycast(origin, Vector3.new(0, -6000, 0), params)
	if not res then
		return nil
	end
	return (origin - res.Position).Magnitude
end

local out = {}

-- CONTROL: a road part must find something close beneath it (deck/pier/ground).
local ctl, ctlN = nil, "none"
for _, rd in ipairs(roads) do
	local d = dropDist(rd)
	if d then
		ctl, ctlN = d, rd.Name
		break
	end
end
if ctl == nil then
	table.insert(out, "CONTROL=FAIL raycast found nothing under ANY road -- probe is broken, ignore results below")
else
	table.insert(out, ("CONTROL=PASS %.1f studs under %s (raycast works)"):format(ctl, ctlN))
end

-- Classify candidates.
local FLOAT_MIN = 60 -- studs of empty air below = floating
local floating, seated, voidBelow = 0, 0, 0
local worst, worstNm, worstPos = -1, "none", nil
local samples = {}
for _, p in ipairs(candidates) do
	local d = dropDist(p)
	if d == nil then
		voidBelow += 1
		if #samples < 8 then
			table.insert(
				samples,
				("%s@%.0f,%.0f,%.0f NOTHING-BELOW"):format(p.Name, p.Position.X, p.Position.Y, p.Position.Z)
			)
		end
	elseif d > FLOAT_MIN then
		floating += 1
		if d > worst then
			worst, worstNm, worstPos = d, p.Name, p.Position
		end
		if #samples < 8 then
			table.insert(
				samples,
				("%s@%.0f,%.0f,%.0f drop=%.0f"):format(p.Name, p.Position.X, p.Position.Y, p.Position.Z, d)
			)
		end
	else
		seated += 1
	end
end

table.insert(
	out,
	("candidates=%d roads=%d | seated=%d floating(>%d)=%d nothingBelow=%d"):format(
		#candidates,
		#roads,
		seated,
		FLOAT_MIN,
		floating,
		voidBelow
	)
)
if worstPos then
	table.insert(
		out,
		("WORST %s drop=%.0f at %.0f,%.0f,%.0f"):format(worstNm, worst, worstPos.X, worstPos.Y, worstPos.Z)
	)
end
for _, s in ipairs(samples) do
	table.insert(out, "  " .. s)
end

-- Name histogram so we can see WHICH generator made them.
local hist = {}
for _, p in ipairs(candidates) do
	local base = p.Name:gsub("_%d+$", "")
	hist[base] = (hist[base] or 0) + 1
end
local hl = {}
for k, v in pairs(hist) do
	table.insert(hl, ("%s=%d"):format(k, v))
end
table.sort(hl)
table.insert(out, "byName: " .. table.concat(hl, " "))

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