How to modify an entity attribute ?

[Vat1n]

Hello,

I recently made an entity called "Cubos" which can be powered when hit by lightning bolt like creepers. I want it to be faster when powered. I know I have to deal with Attributes and AttributeModifier but I don't exactly know how.
Is it correct to use the method "tick()" in the Cubos file ?

 

package fr.vat1n.vatmod.entity.common;

import ...

public class Cubos extends Animal implements PowerableMob {
    private static final EntityDataAccessor<Boolean> DATA_IS_POWERED = SynchedEntityData.defineId(Cubos.class, EntityDataSerializers.BOOLEAN);

    public Cubos(EntityType<? extends Animal> entityType, Level level){
        super(entityType,level);
    }

    protected void defineSynchedData() {
        super.defineSynchedData();
        this.entityData.define(DATA_IS_POWERED, false);
    }
    public void addAdditionalSaveData(CompoundTag pCompound) {
        super.addAdditionalSaveData(pCompound);
        if (this.entityData.get(DATA_IS_POWERED)) {
            pCompound.putBoolean("powered", true);
        }
    }
    public void readAdditionalSaveData(CompoundTag pCompound) {
        super.readAdditionalSaveData(pCompound);
        this.entityData.set(DATA_IS_POWERED, pCompound.getBoolean("powered"));
    }

    @Nullable
    @Override
    public AgeableMob getBreedOffspring(ServerLevel level, AgeableMob mob) {
        return ModEntities.CUBOS.get().create(level);
    }

    @Override
    protected void registerGoals() {
        this.goalSelector.addGoal(0, new FloatGoal(this));
        this.goalSelector.addGoal(1, new PanicGoal(this, 1.5D));
        this.goalSelector.addGoal(2, new BreedGoal(this, 1.0D));
        this.goalSelector.addGoal(3, new TemptGoal(this, 1.25D, Ingredient.of(ModItems.SIWATOR_AXE.get()), false));
    }

    public static AttributeSupplier.Builder createAttributes() {
        return Mob.createMobAttributes().add(Attributes.MAX_HEALTH, 10.0D).add(Attributes.MOVEMENT_SPEED, (double)0.2F);
    }

    public void thunderHit(ServerLevel pLevel, LightningBolt pLightning) {
        super.thunderHit(pLevel, pLightning);
        this.entityData.set(DATA_IS_POWERED, true);
    }

    @Override
    public boolean isPowered() {
        return this.entityData.get(DATA_IS_POWERED);
    }

    @Override
    public void tick() {
        super.tick();
        if(this.entityData.get(DATA_IS_POWERED)){
            //HOW TO CHANGE THE ATTRIBUTES ?
        }
    }
}

 

[warjort]

Look at LivingEntity.collectEquipmentChanges().

That code adds/removes temporary/transient modifiers based on what equipment the entity is wearing or using.

That too runs in LivingEntity.tick() but only on the server - see that code.

 

It can also be done by adding/removing a MobEffect, like potions do.

Edited May 21, 2023 by warjort