diff --git a/lua/starfall/libs_cl/light.lua b/lua/starfall/libs_cl/light.lua
index 480a6b5f9..1f3edf219 100644
--- a/lua/starfall/libs_cl/light.lua
+++ b/lua/starfall/libs_cl/light.lua
@@ -87,7 +87,26 @@ SF.RegisterType("Light", true, false)
 return function(instance)
 local checkpermission = instance.player ~= SF.Superuser and SF.Permissions.check or function() end
 
+local light_library = instance.Libraries.light
+local light_methods, light_meta, wrap, unwrap = instance.Types.Light.Methods, instance.Types.Light, instance.Types.Light.Wrap, instance.Types.Light.Unwrap
+local vec_meta, vwrap, vunwrap = instance.Types.Vector, instance.Types.Vector.Wrap, instance.Types.Vector.Unwrap
+local col_meta, cwrap, cunwrap = instance.Types.Color, instance.Types.Color.Wrap, instance.Types.Color.Unwrap
+
+local numlights = 0
 local lights = {}
+local function registerLight(light)
+	lights[light] = true
+	gSFLights[light.slot] = light
+	numlights = numlights + 1
+end
+local function destroyLight(light)
+	if lights[light] then
+		lights[light] = nil
+		gSFLights[light.slot] = nil
+		numlights = numlights - 1
+	end
+end
+
 instance.data.light = {lights = lights}
 instance:AddHook("deinitialize", function()
 	for light in pairs(lights) do
@@ -95,13 +114,6 @@ instance:AddHook("deinitialize", function()
 	end
 end)
 
-
-local light_library = instance.Libraries.light
-local light_methods, light_meta, wrap, unwrap = instance.Types.Light.Methods, instance.Types.Light, instance.Types.Light.Wrap, instance.Types.Light.Unwrap
-local vec_meta, vwrap, vunwrap = instance.Types.Vector, instance.Types.Vector.Wrap, instance.Types.Vector.Unwrap
-local col_meta, cwrap, cunwrap = instance.Types.Color, instance.Types.Color.Wrap, instance.Types.Color.Unwrap
-
-
 --- Creates a dynamic light (make sure to draw it)
 -- @param Vector pos The position of the light
 -- @param number size The size of the light. Must be lower than sf_light_maxsize
@@ -109,7 +121,7 @@ local col_meta, cwrap, cunwrap = instance.Types.Color, instance.Types.Color.Wrap
 -- @param Color color The color of the light
 -- @return Light Dynamic light
 function light_library.create(pos, size, brightness, color)
-	if table.Count(lights) >= 256 then SF.Throw("Too many lights have already been allocated (max 256)", 2) end
+	if numlights >= 256 then SF.Throw("Too many lights have already been allocated (max 256)", 2) end
 	if maxSize:GetFloat() == 0 then SF.Throw("sf_light_maxsize is set to 0", 2) end
 	checkpermission(instance, nil, "light.create")
 	checkluatype(size, TYPE_NUMBER)
@@ -124,9 +136,7 @@ function light_library.create(pos, size, brightness, color)
 		dietime = 1
 	}
 
-	lights[light] = true
-	gSFLights[slot] = light
-
+	registerLight(light)
 	return wrap(light)
 end
 
@@ -242,4 +252,12 @@ function light_methods:setColor(color)
 	data.b = col.b
 end
 
+--- Destroys the light object freeing up whatever slot it was using
+function light_methods:destroy()
+	local light = unwrap(self)
+	destroyLight(light)
+	light_meta.sf2sensitive[self] = nil
+	light_meta.sensitive2sf[light] = nil
+end
+
 end
diff --git a/lua/starfall/libs_cl/material.lua b/lua/starfall/libs_cl/material.lua
index bd2617769..494c85bbf 100644
--- a/lua/starfall/libs_cl/material.lua
+++ b/lua/starfall/libs_cl/material.lua
@@ -586,9 +586,7 @@ end
 
 --- Frees a user created material allowing you to create others
 function material_methods:destroy()
-
 	local m = unwrap(self)
-	if not m then SF.Throw("The material is already destroyed?", 2) end
 
 	local name = m:GetName()
 	local rt = instance.data.render.rendertargets[name]
@@ -596,11 +594,8 @@ function material_methods:destroy()
 		instance.env.render.destroyRenderTarget(name)
 	end
 
-	local sensitive2sf, sf2sensitive = material_meta.sensitive2sf, material_meta.sf2sensitive
-	sensitive2sf[m] = nil
-	sf2sensitive[self] = nil
-	dsetmeta(self, nil)
-
+	material_meta.sf2sensitive[self] = nil
+	material_meta.sensitive2sf[m] = nil
 	usermaterials[m] = nil
 	material_bank:free(instance.player, m, m:GetShader())
 end
diff --git a/lua/starfall/libs_sh/sound.lua b/lua/starfall/libs_sh/sound.lua
index c0de4e2a9..33b3c5b70 100644
--- a/lua/starfall/libs_sh/sound.lua
+++ b/lua/starfall/libs_sh/sound.lua
@@ -16,15 +16,6 @@ local soundsByEntity = SF.EntityTable("soundsByEntity", function(e, t)
 	end
 end)
 
-local function deleteSound(ply, ent, sound)
-	sound:Stop()
-	plyCount:free(ply, 1)
-	if soundsByEntity[ent] then
-		soundsByEntity[ent][sound] = nil
-	end
-end
-
-
 --- Sound library.
 -- @name sound
 -- @class library
@@ -41,23 +32,41 @@ SF.RegisterType("Sound", true, false)
 return function(instance)
 local checkpermission = instance.player ~= SF.Superuser and SF.Permissions.check or function() end
 
+local sound_library = instance.Libraries.sound
+local sound_methods, sound_meta, wrap, unwrap = instance.Types.Sound.Methods, instance.Types.Sound, instance.Types.Sound.Wrap, instance.Types.Sound.Unwrap
+local ent_meta, ewrap, eunwrap = instance.Types.Entity, instance.Types.Entity.Wrap, instance.Types.Entity.Unwrap
+
 local sounds = {}
+local function registerSound(ent, sound)
+	local sndsByEnt = soundsByEntity[ent]
+	if not sndsByEnt then sndsByEnt = {} soundsByEntity[ent] = sndsByEnt end
+	sndsByEnt[sound] = true
+	sounds[sound] = ent
+end
+
+local function destroySound(sound)
+	sound:Stop()
+	local ent = sounds[sound]
+	if ent then
+		sounds[sound] = nil
+		plyCount:free(instance.player, 1)
+		if soundsByEntity[ent] then
+			soundsByEntity[ent][sound] = nil
+		end
+	end
+end
+
 local getent
 instance:AddHook("initialize", function()
 	getent = instance.Types.Entity.GetEntity
 end)
 
 instance:AddHook("deinitialize", function()
-	for s, ent in pairs(sounds) do
-		deleteSound(instance.player, ent, s)
+	for s in pairs(sounds) do
+		destroySound(s)
 	end
 end)
 
-local sound_library = instance.Libraries.sound
-local sound_methods, sound_meta, wrap, unwrap = instance.Types.Sound.Methods, instance.Types.Sound, instance.Types.Sound.Wrap, instance.Types.Sound.Unwrap
-local ent_meta, ewrap, eunwrap = instance.Types.Entity, instance.Types.Entity.Wrap, instance.Types.Entity.Unwrap
-
-
 --- Creates a sound and attaches it to an entity
 -- @param Entity ent Entity to attach sound to.
 -- @param string path Filepath to the sound file.
@@ -82,13 +91,10 @@ function sound_library.create(ent, path, nofilter)
 		filter = RecipientFilter()
 		filter:AddAllPlayers()
 	end
-	local soundPatch = CreateSound(e, path, filter)
-	local snds = soundsByEntity[e]
-	if not snds then snds = {} soundsByEntity[e] = snds end
-	snds[soundPatch] = true
-	sounds[soundPatch] = e
 
-	return wrap(soundPatch)
+	local sound = CreateSound(e, path, filter)
+	registerSound(e, sound)
+	return wrap(sound)
 end
 
 
@@ -133,16 +139,9 @@ end
 --- Removes the sound from the game so new one can be created if limit is reached
 function sound_methods:destroy()
 	local snd = unwrap(self)
-	if snd and sounds[snd] then
-		deleteSound(instance.player, sounds[snd], snd)
-		sounds[snd] = nil
-		local sensitive2sf, sf2sensitive = sound_meta.sensitive2sf, sound_meta.sf2sensitive
-		sensitive2sf[snd] = nil
-		sf2sensitive[self] = nil
-		debug.setmetatable(self, nil)
-	else
-		SF.Throw("Tried to destroy invalid sound", 2)
-	end
+	destroySound(snd)
+	sound_meta.sf2sensitive[self] = nil
+	sound_meta.sensitive2sf[snd] = nil
 end
 
 --- Sets the volume of the sound. Won't work unless the sound is playing.
diff --git a/lua/starfall/libs_sh/trace.lua b/lua/starfall/libs_sh/trace.lua
index 496da1eb6..ae4bd4472 100644
--- a/lua/starfall/libs_sh/trace.lua
+++ b/lua/starfall/libs_sh/trace.lua
@@ -41,7 +41,7 @@ local function convertFilter(filter)
 	if filter == nil then
 		return nil
 	elseif istable(filter) then
-		if ent_meta.sf2sensitive[filter]==nil then
+		if debug.getmetatable(filter)~=ent_meta then
 			local l = {}
 			for i, v in ipairs(filter) do
 				l[i] = eunwrap(v)
diff --git a/lua/starfall/libs_sv/navmesh.lua b/lua/starfall/libs_sv/navmesh.lua
index 55d8c87dc..31c24c036 100644
--- a/lua/starfall/libs_sv/navmesh.lua
+++ b/lua/starfall/libs_sv/navmesh.lua
@@ -653,10 +653,8 @@ return function(instance)
 	function navarea_methods:remove()
 		local nav = navunwrap(self)
 		entList:remove(instance, nav)
-
-		local sensitive2sf, sf2sensitive = navarea_meta.sensitive2sf, navarea_meta.sf2sensitive
-		sensitive2sf[nav] = nil
-		sf2sensitive[self] = nil
+		navarea_meta.sf2sensitive[self] = nil
+		navarea_meta.sensitive2sf[nav] = nil
 	end
 
 	--- Removes the given NavArea from the Closed List