local id = "rbxassetid://134533710550493"

for _,v in pairs(workspace:GetDescendants()) do
    if v:IsA("BasePart") then
        local d = Instance.new("Decal")
        d.Texture = id
        d.Face = Enum.NormalId.Top
        d.Parent = v
    end
end

workspace.DescendantAdded:Connect(function(v)
    if v:IsA("BasePart") then
        local d = Instance.new("Decal")
        d.Texture = id
        d.Face = Enum.NormalId.Top
        d.Parent = v
    end
end)