What is my world transmission command?

The explanation is as follows:/fill <; Coordinate > Air replaces water.

Although the size of the world is infinite, the range that players can walk out of is limited. There is a world boundary at the X/Z axis 29,999,984 of the Java version of the world. The world boundary is a dynamic blue diagonal wall.

Being close to the world boundary will make the screen red. Except teleportation, most creatures can't cross the world boundary. Players who cross the line will suffer continuous damage unless they are in creative mode. The farthest position that the player can teleport is X/Z axis 29,999,999, and there is an invisible wall here.

Portal:

To reach the lower bound, the player must establish a lower bound portal in the main world (the lower bound terminal portal will send the player back to the main world, and the lower bound portal in the terminal will not be activated).

In order to create the lower entrance, an obsidian frame must be built, with the minimum size of 4×5 and the maximum size of 23×23. Once the obsidian frame is built, the lower portal can be activated by igniting the obsidian inside with flint or flame bomb (or using other methods to ignite obsidian).

As long as there is fire inside obsidian, the portal will be activated. When the lower portal is activated, it will emit purple particles like the particle effect of the last shadow people.