tech_additions/airblock.lua

local S = minetest.get_translator("tech_additions")

local replace_allowed = {}
replace_allowed["air"] = true
replace_allowed["default:water_source"] = true
replace_allowed["default:water_flowing"] = true
replace_allowed["default:river_water_source"] = true
replace_allowed["default:river_water_flowing"] = true

local placeairblock = function ()
	return function(itemstack, user, pointed_thing)
		local name = user:get_player_name()
		if not minetest.is_creative_enabled(name) then
			return
		end

		local pos = user:getpos()
		local dir = user:get_look_dir()
		local distancefromplayer = 3
		local new_pos = {
			x = pos.x + (dir.x * distancefromplayer),
			y = pos.y + 1 + (dir.y * distancefromplayer),
			z = pos.z + (dir.z * distancefromplayer),
		}

		if minetest.is_protected(new_pos, name) then
			minetest.record_protection_violation(new_pos, name)
			return
		end

		local getPos = minetest.get_node(new_pos)
		if replace_allowed[getPos.name] then
			minetest.set_node(new_pos, {name="tech_additions:air_block"})
		end
	end
end

minetest.register_node("tech_additions:air_block", {
    description = S("Air Block"),
    tiles = {"tech_additions_air_block.png"},
      groups = {snappy=3, fall_damage_add_percent = -99, bouncy=70},
      light_source = 30,
      paramtype = "light",
      sunlight_propagates = true,
      on_secondary_use = placeairblock(),
  })