X-Muscle System

by k44dev Software in Scripts and Addons

X-Muscle System is advanced, physics based tissue simulator for Blender.

What is X-Muscle System?

X-Muscle System is an add-on designed for rapid muscular system, tissue and other organic object creation and their physical simulations. Its main purpose is to help visualize better skin surface deformations according to volume preservation of the body muscles, fat and even skeletal bones. Add-on lets you focus on the design, creativity and to significantly speed up the workflow with extremal learning curve. 

With X-Muscle System an artist is free to focus on the artwork and use effectively his time to create even more realistic, complex shapes and animations of characters and creatures. With its simplicity and integration with Blender's native tools, X-Muscle System is powerful, easy in use and ready to start straightaway. X-Muscle System has been designed and written from the scratch and completed with the functionality you always wanted. 

With X-Muscle System add-on purchase some exclusive materials  and services are provided:

  • X-Muscle System Blender add-on download access
  • Anatomy Bundle human male skeleton*, horse skeleton*, cat skeleton*, dog skeleton and carnivore dinosaur skeleton rigged models 
    • all mesh 100% quads
  • access to the documentation, examples and tutorials
  • Product Lifetime Support and Updates

Main system features:

  • animatable muscle parameters like size, properties settings and controllers
  • supports muscle Shape Keys
  • Body meshes with Shape Keys are supported
  • Body meshes with Mirror modifier are supported
  • body auto-weight painting function for muscles and controllers with scope control
  • auto-attach to bones with Auto-Aim mode
  • flexor and extensor muscle type
  • Muscle Pinning Manager and Bendy Muscles with X-Mirror support
  • advanced micro skin Controllers 
  • allows easy muscle mirroring with intelligent X-Mirror feature 
  • vast support for variety types of armatures and custom rigs including Rigify, Pitchipoy, ManuelBastioniLAB, BlenRig5 and Auto-Rig Pro
  • simple but powerful control over the parameters and settings
  • multiple muscles properties adjustment at same time with  real-time execution
  • integrated naming system with powerful renaming feature
  • physically based tissue simulation - jiggling muscles can simulate fat, or particular parts of the body like breast, buttocks, cheeks or skinfolds or rigid body like bones
  • materials management
  • display tools

These are only few features system provides. Refer to the documentation for full specification.

Build high quality, realistic muscle structures with ease

Thanks to flexor and extensor muscle types creating biceps and triceps for your character was never that easy.

Work smart and fast - X-Mirror with single click

With powerful X-Mirror option there's no need to duplicate work. X-Mirror will guarantee excellent symmetry for tissue's shape, properties and behavior saving your effort and time.

Achieve the most complex shapes with Muscle Pinning and Bendy Muscles

Now, with muscle pinning and bendy muscles, tissue shape will follow the bone chain of your rig. Thanks to that, you can create the most advanced and realistic muscular systems.

Inspect your character with provided tools

X-Muscle System provides dedicated Display Tools which allows to work and inspect with ease.

Improve all your existing scenes with the dramatic touch of realism

X-Muscle System works straight away and does not require any preconditions or additional setup so you can start adding great visual experience without reordering your scene.

Start your work with Anatomy Bundle

X-Muscle System comes with rigged human male skeleton model which allows you to immediately exercise your skills.

Bring your digital art back to life!


- updated skeleton models

Current add-on version: 1.9.7

You will get mail notification on every new release

Changelog has been moved to Documentation TAB

*3D Skeleton model should not be used as a real anatomy reference for medical purposes.

**included skeleton model does not contain muscles.

PDF file documentation, examples and video tutorials are available.

Get to official X-Muscle System support video channel

Watch the Shleg demo



Software and Documentation Update

versions 1.9.7

  • new muscle strip type added
  • documentation Update

versions 1.9.3

  • microControllers now x-mirrors correctly when muscles are using pinning, bugfix

versions 1.9.0

  • new Isolate Selected Muscles feature,
  • documentation Update

versions 1.8.9 and 1.8.9a-e:

  • fix exception access violation when Multires was used without shapekeys, a
  • full support for advanced features: bendy muscles and muscle pinning including X-Mirror support, c
  • better mirroring accuracy when scaling is used, c
  • important bugfixes, c
  • X-Mirror support for Bendy Muscles
  • Anatomy Bundle added, c
  • allows to manually reattach muscles attached with auto-aim to other bones and still successfully bind them with the skin. (more flexible workflow in sacrifice of auto-weight painting), d
  • allows to successfully finish binding all the muscles to the skin even when corrupted microController mechanism is detected (accidentally deleted or omitted on muscle duplication), d
  • new Muscle Pinning Panel powerful Manager, e
  • enable and disable viewport/render muscle pinning, e
  • add/remove muscle pins feature, e
  • select pins toggle feature, e
  • reset selected pins feature, e
  • minor bugfixes, e
  • documentation update, e

version 1.8.7 and 1.8.7a:

  • improved Vertex Group management
  • added full support for rename feature after skinning for Vertex Groups and drivers
  • fixed multi-rename failed to work in some cases
  • fixed new muscle Shape is now added to active scene layer only instead to all selected layers
  • change skin model to Object Mode on Micro_Controller toggle
  • fix muscle remains selected after Auto-Aim create
  • fix remove drivers from skin after Micro_Controller disabling
  • muscles will now remain selected after Micro_Controller enable/disable toggle
  • Micro_Controllers will now work even if character object is hidden
  • Documentation Update

version  1.8.3:

  • significantly improved freestyle weightpainting x-mirror
  • fix tension value for Micro_Controller on  x-mirror
  • fix Micro_Controller Set option works now for any Mode 
  • fixed x-mirror muscles if some its parts are hidden
  • minor bugfixes

versions  1.7.9 a-e:

  • fixed critical exception on Micro_Controller deletion, final fix, e
  • muscle size to scale along its local YZ fix, d
  • some default values for muscle properties fix, d
  • perfect symmetry final fix, c
  • perfect symmetry fix (muscle "System" part orientation now mirrored correctly), b
  • fixed property viewport refresh for selected muscle when all parts are selected, a

version  1.7.9:

  • Quick Start - Video Tutorial
  • added full Micro_Controller X-Mirror support feature with X-Mirroring Vertex Groups
  • Documentation Update
  • default muscle create type set to Manual at file startup
  • solved invalid orientation for Micro_Controller in particular scenarios
  • now X-Muscle System works correctly with scaled rig
  • improved pretty Vertex Group naming (dedicated unique naming)
  • fixed unintended settings deletion for all muscles in exceptional scenarios
  • resolved x-mirror with applying body to mesh inverted order
  • Multi-Set support for microControllers feature

Besides new features, this Update contains many bug fixes.

version  1.7.3:

  • added Select Single Muscle function and UI button
  • fixed cleanup orphaned microController
  • added Allow_Duplication and Keep_over_Subdiv setting to the UI
  • Multi-Rename feature added
  • Allow Duplications  feature added with support for X-Mirror and skinning
  • fixed critical exception on microController deletion
  • Documentation Update
  • optimized operation with subsurf in stack
  • Keep over Subdiv feature added
  • autobind microController to the skin feature

Besides new features, this Update contains stability, performance improvements and better scene management.

Is Blender Muscle Tools the same as X-Muscle System?

No, Muscle Tools and X-Muscle System are not the same products. They're different projects and they're not even compatible.

What license is the skeleton model?

All skeleton models are included under Royalty Free License

I already have X-Muscle System Standard, can I upgrade to XL variant?

Yes, for upgrading the add-on contact X-Muscle System support and Blender Market team.

Can X-Muscle System export its muscular system for game engines like Unity or Unreal Engine?

At the moment there are three ways of exporting character's mesh with muscle deformations. First of them is NewTek MDD exporter, which will export shape-keyed animation keyframes. The second one is done via Corrective shape keys. This second method allows to control specific muscle behavior within game engine via bone-driven shape-keys. Both add-ons are provided with blender and need activation in User Preferences. Third one is done by baking displacement map.

How long I will receive new updates?

X-Muscle System customers will be supported for the whole product life-time with all the documentation, video-tutorials, software updates, new features and bug fixes. All future updates and new content are free.

What is the difference between Blender Muscle Tools and X-Muscle System?

X-Muscle System is advanced system for creating character's musculature. It includes multiple automation tools, which can not be find in Muscle Tools. Making the rigging time down from days to minutes allows to focus only on the creative part of the work. The most important exclusive features X-Muscle System provides:

  • Advanced and intelligent X-Mirror
  • autobind feature
  • auto-weight paint feature
  • powerful renaming system
  • multiple muscles control system 
  • easy switch from flexor to extensor muscle type
  • intelligent dynamics cache update
  • intelligent Vertex-Groups Manager
  • intelligent modifiers and drivers management
  • designed for freestyle workflow (symmetrical pose is not required)
  • micro skin Controllers which improves deformation quality and precision
  • supports mesh models with shape-keys and drivers
  • muscle pinning with x-mirror support
  • anatomy bundle included
I want to update! Where are the files?!

Each new version is available for download on Blender Market. Old files are always replaced by new ones. To download the update all you have to do is to download the same files. Add-on as well as documentation are always versioned so if you have any doubts just look for the version numbers in downloaded files.

I made a purchase some time ago but I can not update the add-on because I don't have an account!

In this case please contact Blender Market support. They will help you and instruct step by step how to download the updated files.

My skeleton model is responding very slow when I move it.

Each model has Subsurf modifier enabled by default. Disable the Subsurf for the Viewport in Modifier's section or use the Simplify in the Scene section to simplify the whole scene.

What is X-Muscle System XL variant?

X-Muscle System XL variant is deluxe edition of the add-on including high quality Anatomy Bundle rigged models and Exclusive Early Access to Beta Features.

Current Anatomy Bundle content:

  • cat
  • dog
  • horse
  • human male V1 and V2
  • carnivore dinsaur

Standard add-on version includes one rigged model - human male V1 skeleton

I want more freedom in movement of my model!

Some control bones transformation may be limited by default. If you want more elasticity of your model just unlock transform for Loc Rot or Scale for particular control bones.

Item Rating

This item has an average rating of 5 from 8 ratings by the community.

  • 2b0726d23f5c14b5aa3ed2e1d4e27153

    romkosi about 1 month ago

    Great addon!!! I hope to see this in 2.8)

    • 8823ea85942c545eb08521b91f2c0e55

      k44dev Studio about 1 month ago

      Thank you romkosi! Blender 2.8 is planned to be supported!

  • 8316c9158910db2374364d16442938bd

    sotolink about 1 month ago

    Great addon, hope you make a female skeleton as well.

    • 8823ea85942c545eb08521b91f2c0e55

      k44dev Studio about 1 month ago

      Thank you sotolink! With achieving 300 sales will come more models to Anatomy Bundle, there's a big chance for female skeleton model to come.

  • 5aff122c9ed1a6a99b30080a4c6fdf3c

    Artell about 1 month ago

    Very nice addon, indispensable tool for muscles rigging.

    • 8823ea85942c545eb08521b91f2c0e55

      k44dev Studio about 1 month ago

      Thank you very much!

  • Bbd37dfa4c8ab9ce065e811401717db6

    tomerwei about 1 month ago

    Does not come with actual muscle model, just skeleton. False advertising.

    • 8823ea85942c545eb08521b91f2c0e55

      k44dev Studio about 1 month ago

      Who told you there's anything like muscle model? You paid 35$ for the add on and got rigged skeleton worth 200$ for free and still unhappy. Do you have any real reason to for this rating?

  • F218e677087d0c9123146aae380afc70

    Carlos Puebla 5 months ago

    Excellent Add-on and support ,great work¡¡

    • 8823ea85942c545eb08521b91f2c0e55

      k44dev Studio 5 months ago

      Thank you! There will be even more reasons this week! New models and features coming soon

  • 1a2a41d7361bec4efa40cc5c5623633d

    Forrest 9 months ago

    awesome stuff man, do you have any plans to release a female skeleton model?

    • 8823ea85942c545eb08521b91f2c0e55

      k44dev Studio 9 months ago

      Thank you! There is a plan to expand anatomy bundle with new sort of rigged skeletons including popular animals. Have a good time with X-Muscle System!

  • Thumb

    Vassilis Kakoulantonakis 10 months ago

    Great addon, Works perfectly out of the box!!

    • 8823ea85942c545eb08521b91f2c0e55

      k44dev Studio 10 months ago

      Thank you! Have a good time with X-Muscle System!

  • C57cb235d35a6c1dd7c626bfd6f1b171

    vink about 1 year ago

    Intuitive and easy to setup :)

    • 8823ea85942c545eb08521b91f2c0e55

      k44dev Studio 12 months ago

      Thank you vink!

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