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)