How to stop GUI from appearing when you don't look at the Sun in this script?

before setting the frame's position, check if the screenpos.Z is over 0, I experimented for a while and notice if you look at the opposite of the sun, the frame will appear but the screenpos.Z will be under 0, but if you look at the sun the screenpos.Z will be over 0. Hope this helps

Code:

local s = script.Parent
local gui = script.Parent.Parent
s.Visible = false

local plry = game.Players.LocalPlayer
local char = plry.Character or plry.CharacterAdded:Wait()

local head = char:FindFirstChild("Head") or char:WaitForChild("Head")

local rs = game:GetService("RunService")

rs.RenderStepped:Connect(function()
	local cam = workspace.CurrentCamera
	local lighting = game.Lighting
	local sundir = cam.CFrame.p + lighting:GetSunDirection()
	
	local screenpos = cam:WorldToScreenPoint(sundir)
	
	if not (screenpos.Z > 0) then
		s.Visible = false
		return
	end
	s.Visible = true

	s.Position = UDim2.new(0,screenpos.X,0,screenpos.Y)

	local bupleft = 0 - s.AbsoluteSize.Y
	local bupright = 0 - s.AbsoluteSize.X
	local bdownleft = gui.AbsoluteSize.Y + s.AbsoluteSize.Y
	local bdownright = gui.AbsoluteSize.X + s.AbsoluteSize.X

	local rayprams = RaycastParams.new()
	rayprams.FilterType = Enum.RaycastFilterType.Blacklist
	rayprams.FilterDescendantsInstances = {char}
	local raydir = lighting:GetSunDirection() * 99999
	local raycast = workspace:Raycast(cam.CFrame.Position, raydir, rayprams)

	local ts = game:GetService("TweenService")
	local ti = TweenInfo.new(0.05, Enum.EasingStyle.Linear)
	if raycast and screenpos.Z < 0 and s.AbsolutePosition.X >= (bupleft or bupright) and s.AbsolutePosition.Y <= (bdownleft or bdownright) then
		ts:Create(s, TweenInfo.new(0.01, Enum.EasingStyle.Linear), {Size = UDim2.new(0,0,0,0)}):Play()
	else
		ts:Create(s, ti, {Size = UDim2.new(0,50,0,50)}):Play()
	end
end)