Building

Mobs

A Mob is a custom creature for your server: a golem boss, a raccoon, a beetle. It's a 3D Model that walks around and fights. You can generate one from words, or convert a model you already have, and then choose how it behaves, how tough it is, which animation plays when, what it sounds like, what special attacks it has and what it drops.

Mobs need the RP Engine plugin, 0.2.51 or newer, on your server. Our test server has it.

Generating one from words#

The quickest way to a mob is to describe it.

1. On the pack page, press Add asset, stay on the Model tab, and set What is it to Mob.
2. Describe the creature: "a waffle and cake golem boss with a crocodile jaw", "a raccoon", "a purple cave spider". A reference picture works here as it does for any model.
3. Press Generate (about 113 credits; the exact price is shown under the prompt). It takes roughly 7 to 18 minutes and makes everything in one run: the model, with its head, jaw, legs, tail and wings as separate moving parts; its animations (idle, walk, attack, hurt and death); and its own sounds (an idle call, a hurt yelp, a death cry and an attack). Its card says it's generating, then animating.

If a part of the run fails, you keep the rest and aren't charged for the part that failed: a mob whose animating failed has no animations, and a sound that couldn't be made keeps the vanilla one. The mob editor says what went wrong, and Animate with AI or Generate sounds with AI tries again.

Making one by hand#

1. Make the model. Generate, upload or build it, as on the Models page. Give it bones and animations (walk, idle, attack) in the model editor's Animate mode, because a mob plays them by state.
2. Convert it. On the model's page, press Convert in the header, or right-click the model's card and choose Convert to…, then Mob. The mob editor opens straight away. From then on it's on the pack's Mobs tab rather than under Models.
3. Set it up. A new mob already works: a hostile mob with 20 health. Change what you need and it saves on its own.

Animate with AI#

For a mob you converted from a model. It's at the foot of the mob editor's left column and costs about 25 credits. It splits the model into moving parts (bones), writes one animation for each state you tick, and sets each state to play it.

• What is it, and how does it move? Optional words that steer it: "a heavy golem that stomps and bites", "hops instead of walking".
• Set it up too also chooses the behaviour, health, damage, speed and experience from the description, measures the hitbox off the model, works out which way it faces and picks its head. It's on for a mob that has no animations yet. Off, your settings are left alone and it only animates. For a mob with no abilities yet, it also adds the ones your words ask for: "a boss that slams the ground and summons minions at half health" comes back with a Ground Slam, a phase that calls minions, and an animation for each (up to two, at no extra cost). If an ability wants a VFX or sound the pack doesn't have, that step shows a button to make it, with its price. Nothing extra is generated without you pressing it.
• States to animate: Idle, Walk, Attack, Hurt and Death are ticked to start with. Run and Spawn are there if you want them; a blank Run plays Walk.

Running it again replaces the animations it wrote and keeps any others the model has. It runs in the background, so you can leave the editor and come back.

The mob editor#

The model stands in the middle with its hitbox drawn round it and a blue arrow at its feet showing which way it walks. The states and sounds are on the left, everything else on the right.

Behaviour#

Underneath, a mob is a vanilla mob you can't see, wearing your model. Its behaviour decides which one, and so how it moves and fights.

Burns in daylight is off unless you tick it, whatever the mob walks like. Flashes red when hurt is on: the model goes red for a moment when it takes damage, like a vanilla mob. On servers older than 1.21.4 it shows a red outline instead. Fire immune stops fire and lava hurting it, and Glowing outline gives it the outline a spectral arrow does.

A Ranged mob gets a Shooting section: what it fires (an arrow, a snowball, a small fireball, a fireball, a wither skull or a trident), the damage per hit (0 keeps the projectile's own), and how far away it shoots from. It keeps its distance like a skeleton and plays its Attack animation each time it shoots. A fireball or a skull never breaks blocks.

Stats#

Boss bar#

Turn on Show a boss bar for a bar across the top of the screen with the mob's name and health, shown to every player within Seen within blocks. Pick its colour and how many notches it has.

Spawning#

Turn on Spawns on its own and the mob appears in the world by itself. It takes the place of some of the mobs the game spawns naturally rather than adding to them, so your world never holds more mobs than it would have:

A mob that spawned on its own despawns when nobody is near, the way the mob it replaced would have. One you spawn with a command or an egg stays.

Size and facing#

Model size is how big the model is drawn. Hitbox height is how tall the box it's hit and pushed by is, in blocks; its width grows with it. Press Fit to model to match it to the model at its size. The hitbox needs a 1.20.5 or newer server; older ones keep the vanilla mob's box.

If the mob walks sideways or backwards, use Turn until the blue arrow points out of its face. Head picks a bone that turns to look at what the mob is after. That bone has to move in at least one animation, or it's drawn as part of the body and can't turn.

Animations#

One of the model's animations per state. Press play beside a state to watch it in the editor.

The list is in order of importance: a mob doing several things at once plays the first one listed. The first four play once to the end unless something higher up starts; a blank one simply doesn't play.

Sounds#

Ambient, hurt, death, attack and step, each a sound from the pack. Pick one, or press + to make a new one in the sound editor (it opens in a new tab, and the list updates when you come back). The play button beside a slot plays what it's set to. Setting any of them silences the vanilla mob underneath, so a mob with none set keeps its own sounds. Ambient plays every so often while a player is nearby.

Generate sounds with AI, under the slots, makes the ambient, hurt, death and attack sounds for a mob that doesn't have them, such as one converted from a model. Describe the creature and tick the sounds to make. They come out short, in mono (so they're heard from the mob in game) and at matching volumes, and are saved as ordinary Sounds in the pack, each with a second take to choose from. Each take is charged like generating a Sound; the price is shown before you start.

Abilities#

What it does besides walk and bite: a ground slam every few seconds, minions when it drops below half health, a poison aura, a volley of fireballs, a phase where it goes red and fast. Each ability is three things:

• When: every few seconds, when it's hurt, when it hits something, when it appears, when it finds a target, when it dies, when a player right-clicks it or when it kills a player. Narrow it with Health (Once below 50% runs the moment it first drops under half, which is how a boss changes phase; While below runs every time while it's under) and conditions: only while it has a target, while its target is within or further than so many blocks, while a player is near, in or out of a phase, by day or night, in the rain, on the ground.
• Do: steps, run in order. Play one of its animations, wait, damage, heal, knock back, pull in, leap or lunge at its target, a potion effect, set on fire, summon mobs, enter a phase, play one of the pack's VFX or sounds, particles, a chat message or a title, shoot a projectile, an explosion (it never breaks blocks), lightning, tint the model, change speed, a shield, teleport to its target.
• At whom, per step: itself, its target, whoever set it off, players or everything within so many blocks, the nearest player, everything in front of it, or for effects a spot: where it stands, where its target stands, a spot ahead, a ring of spots, random spots near it.

Plus a cooldown and a chance. Add an ability starts from nothing or from one of six: Ground slam, Summon minions at half health, Leap at its target, Poison aura, Fireball volley and Enrage phase.

Writing abilities as text. The </> button on an ability shows it as skill lines in MythicMobs syntax, which RP Engine runs. The first line says when, every line after it is a step. Lines can use anything RP Engine supports, not only what the form offers (see Skills for the full list), and a line it can't read is pointed out as you type. Press the button again to go back to the form.

Abilities need RP Engine 0.2.53 or newer. On an older version the mob walks and fights without them.

Drops#

What it drops when killed, instead of the vanilla mob's loot: an item, the least and most of it, and the chance it drops at all. Search for any vanilla item, or type studio:<id> for one of the pack's own items. With no drops it drops nothing but its XP.

Spawning it in game#

1. Sync the pack: press Sync and run the /rp sync <code> it shows on a server running RP Engine. That sends the pack, mobs included, to you there. For every player, serve it with Distribution.
2. Press Spawn in game on the model's page (or Give on its card) to get a spawn egg for it. Use the egg on a block to hatch the mob there. This needs a 1.20.5 or newer pack.
3. Or use the commands on the server:

<id> is the model's id, shown on its page.

Bedrock players joining through Geyser see the mob as its model too, animated the same way, from the Bedrock pack a sync sends them (RP Engine 0.2.53 or newer). See Bedrock and Geyser.

Exports#

The mob settings reach RP Engine when you sync the pack or serve it with Distribution. An exported Java .zip carries them too (in its studio-content.json), and RP Engine reads them when the zip is dropped into its content/ folder. The other exports carry the model, but not the mob.