Introduction to AOE Clouds

Area-of-effect clouds, also known as AOE clouds and minecraft:area_effect_cloud internally, are special entities that have many unique properties. Normally these entities are created through throwing lingering potions, but with structures and some NBT editing magic we can manipulate them in very powerful ways for map-making.

Overview ​

AOE clouds have several special features we can take advantage of:

• As dummy entities, AOE clouds are highly performant. They are optimized to have no collision with the world or other entities. This makes them perfect for situations around players or other entities.
• AOE clouds are perfectly static and can only be moved with commands. This is ideal for situations where precise positioning is important.
• AOE clouds can be configured to apply potion effects. The duration can be set down to the tick, as well as whether or not the effect is ambient, if it displays on the screen, if it emits particles, etc.
• Entities with a runtime identifier of minecraft:area_effect_cloud inherit these same properties.

Placing AOE Clouds ​

To create an AOE cloud, we need to first create a structure to contain one. An AOE cloud must have specific NBT data in order to exist properly.

NBT Editors ​

One of the following NBT editors are recommended for editing structure files:

• NBT Studio (a standalone program by tryashtar)
• NBT Viewer (a Visual Studio Code extension by Misode)

Structure file ​

For convenience, this article contains a premade structure file you can download and use. Inside is an AOE cloud with the smallest possible radius (0.5 blocks) that exists for the maximum possible time (2^31 - 1 ticks, or about 29,826 hours).

Refer to this article for editing structure files: .mcstructure

NBT Format ​

Below are the parameters for the mobEffects tag.

Using AOE Clouds ​

Once an AOE cloud is placed, we can then use it like any other marker/dummy entity.

Some things to consider when using an AOE cloud:

• They use the particle emitter minecraft:mobspell_lingering. To avoid seeing particles, a resource pack must alter this particle emitter.
• The entity minecraft:area_effect_cloud does not send the client updates about its position; this means it will appear fixed to where it spawned in. It can still be moved around with /teleport.

Scripting Utility ​

To make manipulating AOE clouds easier, the following utility is provided. It exports a function, registerOnEntityLoad, that invokes a callback when an entity loads in. This can be used to access the AOE cloud after deferring its spawning to the structure manager.

import { world, DimensionLocation } from "@minecraft/server";
import { registerOnEntityLoad } from "./entity_load_handler.js";

/**
 * @param {DimensionLocation} location
 */
function spawnMarker(location) {
    const Structure_Location = {
        x: Math.floor(location.x),
        y: Math.floor(location.y),
        z: Math.floor(location.z)
    };
    world.structureManager.place(
        "mystructure:aec",
        location.dimension,
        Structure_Location,
    );
    registerOnEntityLoad(
        "minecraft:area_effect_cloud",
        function initializeMarker(entity) {
            const Entity_Location = {
                x: location.x,
                y: location.y,
                z: location.z
            };
            entity.teleport(Entity_Location);
            entity.addTag("origin");
            // etc.
        }
    );
}