block-game / ServerScriptService / CmdrCommands / ChunkCullWorld.lua

return {
	Name = "chunkcull",
	Aliases = {"cullchunks", "resetchunks"},
	Description = "Unload all server chunk cache instantly, then preload only chunks near players (and force clients to unload/resync).",
	Group = "Admin",
	Args = {
		{
			Type = "integer",
			Name = "radius",
			Description = "Horizontal chunk radius around each player to preload",
			Optional = true,
			Default = 5,
		},
		{
			Type = "integer",
			Name = "yRadius",
			Description = "Vertical chunk radius around each player to preload",
			Optional = true,
			Default = 1,
		},
	},
	Run = function(context, radius, yRadius)
		local ReplicatedStorage = game:GetService("ReplicatedStorage")
		local Players = game:GetService("Players")

		local terrainGen = require(
			game:GetService("ServerScriptService")
				:WaitForChild("Actor")
				:WaitForChild("ServerChunkManager")
				:WaitForChild("TerrainGen")
		)

		local tickRemote = ReplicatedStorage:WaitForChild("Tick")

		local r = radius or 5
		local ry = yRadius or 1

		local unloaded = 0
		pcall(function()
			unloaded = terrainGen:UnloadAllChunks()
		end)

		-- Tell all clients to immediately drop their local chunk instances
		pcall(function()
			tickRemote:FireAllClients("U_ALL", 0, 0, 0, 0, 0, 0, 0)
		end)

		-- Preload server chunks around players (reduces initial lag spikes after cull)
		local preloaded = 0
		pcall(function()
			preloaded = terrainGen:PreloadNearPlayers(r, ry)
		end)

		-- Force clients to resync around themselves
		local resyncCount = 0
		for _, player in ipairs(Players:GetPlayers()) do
			local character = player.Character
			local root = character and character:FindFirstChild("HumanoidRootPart")
			if root then
				local pos = root.Position
				local cx = math.floor((pos.X + 16) / 32)
				local cy = math.floor((pos.Y + 16) / 32)
				local cz = math.floor((pos.Z + 16) / 32)
				for y = -ry, ry do
					for x = -r, r do
						for z = -r, r do
							tickRemote:FireClient(player, "C_R", cx + x, cy + y, cz + z, 0, 0, 0, 0)
							resyncCount += 1
						end
					end
				end
			end
		end

		return (
			"chunkcull done | unloaded=%d | preloaded=%d | resyncPackets=%d | radius=%d yRadius=%d"
		):format(unloaded, preloaded, resyncCount, r, ry)
	end,
}