local cam = workspace.CurrentCamera
print("viewport:", cam.ViewportSize.X, cam.ViewportSize.Y)
print("fov:", cam.FieldOfView)
for _,p in ipairs(game:GetService("Players"):GetChildren()) do
    if p ~= game.Players.LocalPlayer and p.Character and p.Character:FindFirstChild("HumanoidRootPart") then
        local root = p.Character.HumanoidRootPart
        local pos, on = cam:WorldToScreenPoint(root.Position)
        if on then
            local cf, sz = p.Character:GetBoundingBox()
            local top = cam:WorldToScreenPoint(cf.Position + Vector3.yAxis * (sz.Y / 2))
            local bot = cam:WorldToScreenPoint(cf.Position - Vector3.yAxis * (sz.Y / 2))
            local sf = 15 / (pos.Z * math.tan(math.rad(cam.FieldOfView * 0.5)) * 2) * 100
            print(string.format("%-20s rootY=%d topY=%d botY=%d  span=%.1fpx  sizeY=%.2f  rootH=%.2f  sf=%.2f  oldBot=%.1f  warnBot=%.1f",
                p.Name, pos.Y, top.Y, bot.Y, bot.Y - top.Y, sz.Y, root.Position.Y - bot.Y / 0 + 0, sf, pos.Y + (3.79 * sf) / 1.6, bot.Y))
        end
    end
end