Help with cframing parts with lookvector of the camera?

I'm trying to make cartoon effects to this tiny map, where the border of the block is black. You should never see a black part in front of any part. How do you do this to the camera?

So far, this is what I managed. Yet, the parts stay and don't move away from the cam.

local plr=game.Players.LocalPlayer.Character
local cam=Workspace.CurrentCamera
game:GetService('RunService').Stepped:connect(function()
    if cam:findFirstChild("Carto")~=nil then
        cam.Carto:Destroy()
    end
    n=Instance.new("Model",cam) n.Name="Carto"
    local all=Workspace.Model:getChildren()
    for a=1,#all do
        local p=all[a]:Clone()
        p.CFrame=all[a].CFrame+Vector3.new(cam.CoordinateFrame)
        p.Parent=cam.Carto
    end
end)