MECHA – Multiple Entity Collision Hitboxes API

A simple API for enabling custom entities to implement more than one collision box.

Setup

Add the Modrinth Maven and the right version of the mod to your build.gradle file:

repositories {
	maven { url 'https://api.modrinth.com/maven' }
}

dependencies {
	modImplementation "maven.modrinth:mecha-api:VERSION_GOES_HERE"
}

Usage

Implement MultiCollidable in your custom entity class, and override getColliders to add extra colliders to the entity.

Example

The following example code adds 2 colliders to an entity, each the size of a slab:

public CustomEntity extends Entity implements MultiCollidable {
    public List<VoxelShape> getColliders() {
        List<VoxelShape> colliders = new ArrayList<>();
        BlockPos pos = this.blockPos();
        double x = pos.getX();
        double y = pos.getY();
        double z = pos.getZ();
        colliders.add(VoxelShapes.cuboid(x, y, z, x+1, y+0.5, z+1));
        colliders.add(VoxelShapes.cuboid(x, y+0.5, z, x+1, y+1, z+1));
        return colliders;
    }
}

For 0.1.2 and newer, there is now also a custom entity type, DynamicBoundingBoxEntity, which has a dynamic bounding box based on the list returned by getColliders():

public CustomEntity extends DynamicBoundingBoxEntity {
    // The bounding box of this entity will dynamically resize
    // to fit the colliders returned by this function
    @Override
    public List<VoxelShape> getColliders() { ... }
}