Minetest - Flash screen

init.lua

minetest.register_craftitem("mymod:myitem", {
	description = "Flash",
	inventory_image = "default_wood.png",
	on_use = function(itemstack, user, pointed_thing)
		if not user:is_player() then return end
		local plname = user:get_player_name()
		local hud_id = user:hud_add({
			hud_elem_type = "image",
			position = {x=0, y=0},
			text = "mymod_flash.png",
			alignment = {x=1, y=1},
			scale = {x=-100, y=-100},
		})
		-- Remove "flash" after one second.
		minetest.after(1, function()
			user:hud_remove(hud_id)
		end)
		user:set_hp(user:get_hp() + 4)
	end,
})