Generate a YGOPro Lua script for the following Yu-Gi-Oh card effect:
All monsters on the field and in the GYs become Zombie monsters. Neither player can Tribute Summon monsters, except Zombie monsters.
--アンデットワールド
--Zombie World
local s,id=GetID()
function s.initial_effect(c)
	--Activate
	local e1=Effect.CreateEffect(c)
	e1:SetType(EFFECT_TYPE_ACTIVATE)
	e1:SetCode(EVENT_FREE_CHAIN)
	c:RegisterEffect(e1)
	--race
	local e2=Effect.CreateEffect(c)
	e2:SetType(EFFECT_TYPE_FIELD)
	e2:SetRange(LOCATION_FZONE)
	e2:SetTargetRange(LOCATION_MZONE|LOCATION_GRAVE,LOCATION_MZONE|LOCATION_GRAVE)
	e2:SetCode(EFFECT_CHANGE_RACE)
	e2:SetValue(RACE_ZOMBIE)
	e2:SetTarget(s.tg)
	c:RegisterEffect(e2)
	--summon limit
	local e3=Effect.CreateEffect(c)
	e3:SetType(EFFECT_TYPE_FIELD)
	e3:SetRange(LOCATION_FZONE)
	e3:SetCode(EFFECT_CANNOT_SUMMON)
	e3:SetProperty(EFFECT_FLAG_PLAYER_TARGET)
	e3:SetTargetRange(1,1)
	e3:SetTarget(s.sumlimit)
	c:RegisterEffect(e3)
	local e4=e3:Clone()
	e4:SetCode(EFFECT_CANNOT_MSET)
	c:RegisterEffect(e4)
	--id chk
	local e5=Effect.CreateEffect(c)
	e5:SetType(EFFECT_TYPE_FIELD)
	e5:SetCode(id)
	e5:SetRange(LOCATION_FZONE)
	e5:SetProperty(EFFECT_FLAG_PLAYER_TARGET)
	e5:SetTargetRange(1,1)
	e5:SetValue(s.val)
	c:RegisterEffect(e5)
end
function s.tg(e,c)
	if c:GetFlagEffect(1)==0 then
		c:RegisterFlagEffect(1,0,0,0)
		local eff
		if c:IsLocation(LOCATION_MZONE) then
			eff={Duel.GetPlayerEffect(c:GetControler(),EFFECT_NECRO_VALLEY)}
		else
			eff={c:GetCardEffect(EFFECT_NECRO_VALLEY)}
		end
		c:ResetFlagEffect(1)
		for _,te in ipairs(eff) do
			local op=te:GetOperation()
			if not op or op(e,c) then return false end
		end
	end
	return true
end
function s.val(e,c,re,chk)
	if chk==0 then return true end
	return RACE_ZOMBIE
end
function s.sumlimit(e,c,tp,sumtp)
	return sumtp&SUMMON_TYPE_TRIBUTE==SUMMON_TYPE_TRIBUTE and not c:IsRace(RACE_ZOMBIE)
end