Why wont my camera interpolate?

I'm trying to use camera:Interpolate() as an alternative to my usual clunky camera manipulation. However, whenever I call it Nothing Happens . I've tried all I can think of. Thank you for any help!

local player = game:GetService("Players").LocalPlayer 
local camera = game.Workspace.CurrentCamera
local T3 =  game.Workspace.RoomTarget1
local T4 =  game.Workspace.RoomTarget2
camera.CameraType = Enum.CameraType.Scriptable

function RoomCam()
camera.CoordinateFrame = CFrame.new(T3.Position)
camera.Focus = T4.CFrame
--camera:Interpolate(CFrame.new(T4.Position),CFrame.new(T3.Position),3)
camera:Interpolate(T4.CFrame, T4.CFrame + T4.CFrame.lookVector, 3)
wait(0.1)
script.Timer.Value = 0
end

if script.Trigger.Value == 1 then
    IntroCam()
elseif script.Trigger.Value == 2 then
    RoomCam()
end