Do you know the portal?

Before the survival test Alpha 1.2.0, Notch suggested that evil spirits might refresh near the portal in the lower bound of the main world. [6] But Jeb later said that the idea was not applied. [7] But in the snapshot 12w22a, zombie pigs are rarely generated near the portal. If you travel between the main world and the lower bound, the direction you face will not change (if you face south when you enter the lower bound, you will still face south after you enter the lower bound). Similarly, if you enter the portal while flying in creative mode, you are still flying when you come out. The portal generated by the game may form a 90-degree angle with the original portal. Even if the artificially built lower portal only uses 10 orbis (simple structure), another portal generated by the game will have 14 orbis (complete mechanism). You can collect four obsidians to make obsidian a renewable resource. If you don't have flint, all the portals in the lower bound are closed, or you can open the portals with evil fireballs. On the contrary, an open door will be closed by a fireball. If you throw the snowball into the entrance below, it will break. Inlet blocks are considered as solid blocks. You can't see the water behind you through the portal box below. This makes the squid obvious. Similarly, you can't see the lower portal box behind you through the water.

Similar to glass, when the lower entrance boxes are stacked, the blocked boxes become invisible. In the creative mode of Beta 1.8, when the lower portal box is destroyed, the sound of broken glass will also be heard. The piston can't push the lower door frame. After the player teleports to another dimension, the time of other dimensions will not pass. If the player enters the portal and activates TNT, TNT will not explode until the player returns. Similarly, the combustion progress of the furnace and the Redstone circuit will also be suspended. If the game crashes during transmission, the player's inventory column will be emptied and reborn at the rebirth point. If the player dies while standing in the lower portal box (such as being burned to death), the dropped items will appear on the main portal. (The main portal refers to the portal in the main world that will be transmitted when multiple portals in the main world are connected to the portal in the same lower bound and enter the portal in the lower bound. Players can enter the lower bound by using a separately placed lower bound portal box. The size and frequency of the sound emitted by the lower portal will decrease with the increase of the distance from the portal, and disappear completely around 15 meters. Before 1.0.0, to close the portal without destroying the structure of the lower portal, water or magma can be poured into the portal, but water cannot be put in the lower portal. This feature was removed after 1.0.0, but placing a water cube in the portal frame can still close the portal. The lower portal cannot connect. This means that two connected portal frames cannot be opened at the same time, and it also means that long portal frames cannot be used as handicrafts (such as wormholes). You can't pause the game through the pause key (default Esc) during transmission, but you can pause the game by moving the window focus (such as Alt+Tab). In the creative mode of Beta 1.8, the portal box can be destroyed like other boxes, and the glass will be broken. The minimum requirements for building the lower portal are only 4 iron ingots and 1 flint. Three iron ingots are used to synthesize a barrel, and the remaining 1 iron ingots and 1 flint are used to synthesize flint. Firstly, the mold is built according to the model of the lower portal frame, the magma is poured into the mold with a bucket, and then the magma is cooled with water to form the obsidian frame. Finally, remove the mold and open the entrance with flint. This method is the most convenient to implement next to the magma lake. When you return to the main world from the lower bound, there will be a chance of failure: although there is already a qualified main world portal, the game has generated a new one. When teleportation is about to happen, the player will destroy the cube as quickly as in water. After 1. 1, the next mouth can't be opened in a dead end. If the player builds a portal in the lower world, but appears in the sea of the main world, the portal will provide you with 4 pieces of obsidian for you to stand and avoid falling. Sometimes, according to the transmission algorithm, players will stand in a newly generated underground portal when they are transported to the lower bound and come back. If the four lower bound entrances are made into a square array with four sides, these entrances will also work. However, this array sometimes has a loophole that prevents players from taking things out of the item bar. Things piled up in the goods column can never be separated. If the flare from the transmitter hits the lower entrance, it will disappear immediately. In the tutorial world of Xbox 360 version, there is a "My World" logo of the lower bound portal.