function line_of_sight(self, pos1, pos2, stepsize)

    stepsize = stepsize or 1

    local s, pos = minetest.line_of_sight(pos1, pos2, stepsize)

    -- normal walking and flying mobs can see you through air
    if s == true then
        return true
    end

    -- New pos1 to be analyzed
    local npos1 = {x = pos1.x, y = pos1.y, z = pos1.z}

    local r, pos = minetest.line_of_sight(npos1, pos2, stepsize)

    -- Checks the return
    if r == true then return true end

    -- Nodename found
    local nn = minetest.get_node(pos).name

    -- Target Distance (td) to travel
    local td = get_distance(pos1, pos2)

    -- Actual Distance (ad) traveled
    local ad = 0

    -- It continues to advance in the line of sight in search of a real obstruction.
    while minetest.registered_nodes[nn] and (minetest.registered_nodes[nn].walkable == false or nn == "default:snow") do

        -- Check if you can still move forward
        if td < ad + stepsize then
            return true -- Reached the target
        end

        -- Moves the analyzed pos
        local d = get_distance(pos1, pos2)
        npos1.x = ((pos2.x - pos1.x) / d * stepsize) + pos1.x
        npos1.y = ((pos2.y - pos1.y) / d * stepsize) + pos1.y
        npos1.z = ((pos2.z - pos1.z) / d * stepsize) + pos1.z

        ad = ad + stepsize

        -- scan again
        r, pos = minetest.line_of_sight(npos1, pos2, stepsize)

        if r == true then return true end

        -- New Nodename found
        nn = minetest.get_node(pos).name

    end

    return false
end