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wtf is mikumikuphysics?

chris0214/mikumikuphysics — explained in plain English

Analysis updated 2026-05-18

35PythonAudience · designerComplexity · 3/5LicenseSetup · moderate

TL;DR

A Blender plugin that simulates realistic hair, skirt, and chain physics for imported MMD character models.

Mindmap

mindmap
  root((MikuMikuPhysics))
    What it does
      Simulates MMD physics
      Real time preview
      Bakes to keyframes
    Tech stack
      Python
      Blender
      Bullet Physics
    Use cases
      Hair and skirt motion
      Multi character scenes
    Audience
      Animators
      MMD creators

Code map

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filefunction / class

Why would anyone build with this?

REASON 1

Add realistic hair, skirt, and chain physics to an MMD character imported into Blender.

REASON 2

Preview physics behavior live while posing or animating a character.

REASON 3

Bake simulated physics into Blender keyframes for a final rendered animation.

REASON 4

Animate scenes with multiple MMD characters that collide with each other.

What's in the stack?

PythonBlenderBullet PhysicsC++

How it stacks up

chris0214/mikumikuphysicsalex-nlp/denoiserlbytedance-seed/cola-dlm
Stars353535
LanguagePythonPythonPython
Setup difficultymoderatehardhard
Complexity3/55/54/5
Audiencedesignerresearcherresearcher

Figures from each repo's GitHub metadata at analysis time.

How do you spin it up?

Difficulty · moderate Time to first run · 30min

Requires Blender 4.2+ and a model already imported with mmd_tools before physics can run.

Licensed under GPL-3.0, meaning you can use and modify it freely, but any distributed derivative work must also be open source under a compatible license.

Wtf does this do

MikuMikuPhysics is a plugin for Blender 4.2 and newer that adds real-time physics simulation for MMD (MikuMikuDance) character models. MMD is a free animation software popular in Japan for animating virtual characters, and models in the PMX format often have physics-driven elements like hair, skirts, and chains that should move naturally. This plugin reads those physics definitions from a PMX model imported into Blender and simulates them using the Bullet physics engine, the same engine MMD itself uses, so the results look close to the original software. You can preview the simulation in real time as you pose or animate the character, see hair and clothing react to movement, and then bake the physics results into Blender keyframes for final rendering. It also handles multiple characters in a scene, letting them collide with each other. You would use this if you are creating Blender animations using MMD character models and want the physics-driven parts of the character to behave naturally rather than staying static. Python is required, and the plugin is installed through Blender's standard add-on system.

Yoink these prompts

Prompt 1
Show me how to install MikuMikuPhysics as a Blender add-on and load an MMD model.
Prompt 2
Walk me through baking a physics simulation into keyframes in MikuMikuPhysics.
Prompt 3
Explain the difference between Independent Worlds and Shadow Collision modes.
Prompt 4
How do I fix jittery hair or skirt physics when dragging a bone in pose mode?
Prompt 5
What quality preset should I use for a complex character with many chains?

Frequently asked questions

wtf is mikumikuphysics?

A Blender plugin that simulates realistic hair, skirt, and chain physics for imported MMD character models.

What language is mikumikuphysics written in?

Mainly Python. The stack also includes Python, Blender, Bullet Physics.

What license does mikumikuphysics use?

Licensed under GPL-3.0, meaning you can use and modify it freely, but any distributed derivative work must also be open source under a compatible license.

How hard is mikumikuphysics to set up?

Setup difficulty is rated moderate, with roughly 30min to a first successful run.

Who is mikumikuphysics for?

Mainly designer.

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