Entity Movement

In Minecraft, entities have the ability to move through the world, either by walking, swimming or flying. To get these behaviors, your entity will generally need quite a few behaviors, broken out into various types.

As you read this tutorial, keep in mind that your entity will need at least:

• A component that sets the entities movement speed.
• A component to set how the entity will move (walking, flying, etc)
• A component to set the entities navigation abilities, so it can generate paths.
• A component that sets where/when the entity should move (AI Goals).

Movement Speed #

The first thing your entity needs is a speed component. This sets how quickly your entity will move through the world.

You should always include minecraft:movement. Add the other two as needed.

All vanilla "swimming" entities like Dolphin include underwater_movement. Only some flying entities have flying_speed. It is not known why this is the case.

Movement Type #

Your entity will also need a movement type. Movement types set hard-coded behavior for how your entity will move through the world.

You may only include one movement type in your entity. Select the component that most closely matches your needs. Generally basic, amphibious and fly are good ones to use.

Movement Modifiers #

Movement modifiers provide additional information about how your entity will move through the world. These components are not required for normal entities, but you should be aware of them.

Navigation #

The next thing your entity needs is a navigation component. Navigation components have quite a few fields, like whether the entity can open doors or avoid sunlight. How you set these fields is generally more important than the navigation component you pick!

The reason there are so many navigation components is that each one gives a slightly different hard-coded behavior. Pick the navigation component whose name/description best matches the kind of navigation your entity will be doing.

You can only have one navigation component at any given time.

Navigation Abilities #

On top of the movement and the navigation component, there exist many additional components to augment the abilities of your entity as they move through the world.

There are also components like minecraft:preferred_path, which will modify navigation based on block-based path-cost.

AI Goals #

The navigation component tells the entity how to generate paths, but it doesn't say when or where to generate paths. This is what the AI components are for.

AI Goals are prefixed with behavior and follow a priority system to pick which behavior to run. The lower priorities will be picked first.

In general, you should usually add quite a few AI components, with different priorities. Layered together, these will create realistic movement and behavior for your entity. As always, vanilla entities provide a good template for which components to add, and with what properties/priorities.

There are too many AI components that generate paths to list in this document. A few will be provided as examples:

For a full list, visit bedrock.dev.

Pathfinding #

Making entities go to specific places is one of the most common requests for Marketplace content. The best way to do pathfinding uses a second entity, which the first entity will be attracted to. I am going to call this secondary entity the marker. If you are confused on how to create a marker, visit the Dummy Entities page.

Idea #

The way we are going to do pathfinding is actually fairly simple: Make our entity aggressive towards our marker, and then simply place our marker where we want our entity to path to. The hard part is knowing what components to add so we get really long-range pathing.

Components #

These components can be edited as needed to create good pathing. Make sure to update the nearest_attackable_target to point to your marker entity. This takes a family_type, so you should set one of those on your marker.

Don't forget to add some basic movement and navigation components so your entity is able to move.

"minecraft:behavior.nearest_attackable_target": {
    "priority": 0,
    "reselect_targets": true,
    "target_search_height": 1000,
    "within_radius": 1000,
    "must_see": false,
    "entity_types": [
        {
            "filters": [
                {
                    "test": "is_family",
                    "subject": "other",
                    "value": "waypoint_1"
                }
            ],
            "max_dist": 1000
        }
    ]
},
"minecraft:attack": {
    "damage": 0
},
"minecraft:behavior.melee_attack": {
    "priority": 0,
    "require_complete_path": true,
    "track_target": true
},
"minecraft:follow_range": {
    "value": 1000,
    "max": 1000
}

Detecting a reached waypoint #

You can use minecraft:target_nearby_sensor to detect when you have reached the marker entity:

"minecraft:target_nearby_sensor": {
    "inside_range": 2.0,
    "outside_range": 4.0,
    "must_see": true,
    "on_inside_range": {
        "event": "reached_waypoint"
    },
    "on_outside_range": {
        "event": "not_reached_waypoint"
    }
}

Other #