Spawn Control

Entity Spawning Control (FORGE ONLY) 🌱

EntityJS provides powerful tools for controlling entity spawning in Minecraft. Using the spawnPlacement feature, you can define precise conditions for entity spawns, while the biomeSpawns event allows for easy additions or removals of biome spawns without needing predicates.

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Key Concepts 🔑

🌍 Spawn Conditions	Define conditions for spawning, such as biome type, light level, time of day, and proximity to specific blocks.
🔄 Spawn Rates	Set the frequency of entity spawns based on specific conditions to control entity density.
📍 Spawn Locations	Specify where entities can spawn, including biomes, dimensions, or custom-defined areas.

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Example of biomeSpawns 🗺️

The biomeSpawns event allows you to add or remove entity spawns in specific biomes. This event is useful for simple modifications without predicate conditions. Changes require a full world restart.

//biomeSpawns Server Script
EntityJSEvents.biomeSpawns(event => {
    event.addSpawn('kubejs:sasuke', ['#minecraft:is_overworld'], 20, 3, 5);
    event.addSpawn('kubejs:wyrm', ['#minecraft:is_overworld'], 20, 3, 5);
    event.addSpawn('minecraft:wither_skeleton', ['#minecraft:is_overworld'], 20, 3, 5);

    event.removeSpawn('minecraft:zombie', ['#minecraft:is_overworld']);
});

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Example of spawnPlacement 🎯

The spawnPlacement feature is used to customize spawning more precisely. You can add custom conditions, apply predicates, or replace spawn rules for specific entity types. The following script demonstrates logical conditions (and, or, replace) for entity spawns.

//spawnPlacement Startup Script
EntityJSEvents.spawnPlacement(event => {
    // Add an "and" predicate: Only allow drowned to spawn above y level 44
    event.and('minecraft:drowned', (entitypredicate, levelaccessor, spawntype, blockpos, randomsource) => {
        return blockpos.y > 44;
    });

    // Add an "or" predicate: Allow enderman to spawn outside the End dimension
    event.or('minecraft:enderman', (entitypredicate, levelaccessor, spawntype, blockpos, randomsource) => {
        return levelaccessor.level.dimension != 'minecraft:the_end';
    });

    // Replace spawn rules: Allow blaze spawns in the Overworld
    event.replace('minecraft:blaze', 'no_restrictions', 'world_surface', (entitypredicate, levelaccessor, spawntype, blockpos, randomsource) => {
        return levelaccessor.level.dimension == 'minecraft:overworld';
    });
});

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Key Takeaways 📌

• Use biomeSpawns for simple additions and removals of biome spawns.
• Use spawnPlacement to apply more precise conditions or replace existing spawn rules.
• A full world restart is required for changes to take effect.