MoLang

Every value in an emote is normally a fixed number you set on a keyframe. MoLang lets you write a little formula in place of that number, and the game solves it on every single frame while the emote plays.

That's how an emote reacts to what's going on — like how long it has been playing, whether the player is sneaking, what time it is in the world — and how you build movement that would be miserable to keyframe by hand.

You don't need to know how to code. A MoLang expression is one line of maths.

Where you write it

Anywhere a keyframe takes a number, you can put an expression instead — in Blockbench, type it into the keyframe's X, Y or Z field. In the emote file it ends up as a string:

"rotation": {
    "vector": [0, "q.anim_time * 20", 0]
}

warning

The old Emotecraft format — a .json with an emote object instead of animations — only understands plain numbers. MoLang works in emotes made in Blockbench or Blender.

Your first expression

q.anim_time is how long the emote has been playing, in seconds. On its own it counts up: 0.5, 1.0, 1.5…

Put it in the body's Y rotation and multiply it:

"body": {
    "rotation": {
        "vector": [0, "q.anim_time * 20", 0]
    }
}

The body now turns 20 degrees every second, forever, and you never placed a second keyframe. Make the number bigger to spin faster, negative to spin the other way.

Making something wave

Multiplying by time grows forever. To make a value go back and forth, use a sine wave:

math.sin(q.anim_time * 200) * 30

Read it right to left: math.sin swings smoothly between -1 and 1, * 30 stretches that to -30–30 degrees, and the 200 inside controls how fast it swings.

Drop that into an arm's Z rotation and the arm waves. Change 30 for how far it swings, change 200 for how quickly.

Reacting to the player

q. values are things the game tells you about the player. They cost you nothing to read:

q.is_sneaking ? 20 : 0

That means if the player is sneaking, use 20, otherwise use 0. Yes-or-no values like q.is_sneaking are just 1 and 0, and ? : picks between two options.

You can combine the two ideas — wave only while sneaking:

q.is_sneaking ? math.sin(q.anim_time * 200) * 30 : 0

There are around seventy of these values, from q.health and q.is_on_fire to q.moon_phase.

Reusing a value

If the same piece of maths shows up in several places, give it a name with v., separate the steps with ;, and hand back the final value with return:

v.wave = math.sin(q.anim_time * 200); return v.wave * 30;

Names you make up live in v. and stick around for as long as the emote plays, so a value you set on one bone can be read on another.

Things that trip people up

• Rotations are in degrees, exactly like a normal keyframe value. 90 is a quarter turn, not 1.57.
• A misspelled query is silently 0. Nothing warns you — the bone just sits there. If an expression does nothing at all, check the spelling first.
• It's a string. In the file the expression goes in quotes; a bare number doesn't.
• It runs every frame, so what you write is a description of the pose at this instant, not a sequence of steps.

Everything else

The full list — every q. value, every math. function, and the easing functions — lives on the PAL MoLang page, because the library is what actually runs it.

Emotecraft implements all of Bedrock's MoLang queries and functions, so the Bedrock MoLang documentation applies too.