CATS for up to Blender 3.6
CATS for Blender 4 and later
Avatar Toolkit
In the near future CATS will be deprecated and replaced by a new addon called “Avatar Toolkit”. As of now (Nov 2025) Avatar Toolkit is in Alpha and may contain bugs. So: - keep using CATs for important VRChat work. - test Avatar Toolkit and report any bugs and issues to help the development of the new addon.
CATS Tutorial by Samaye
CATS addon for Blender - Overview
The CATS addon for Blender is a comprehensive collection of tools originally designed for simplifying the creation of 3D models for use with VRChat (a social VR platform where users can create and interact with custom avatars and worlds). Due to the many features of the addon, usage outside of VRChat is also common.
Here are some key features of the CATS addon:
- Model Optimization:
- Bone Merging and Cleaning: Simplifies the rigging process by merging unnecessary bones and cleaning up the rig structure.
- Mesh Optimization: Reduces polygon count and optimizes the mesh for better performance in VRChat.
- Rigging Tools:
- Automatic Eye Tracking: Adds eye tracking functionality to models.
- Visemes and Lip Sync: Implements shape keys for lip-syncing and facial expressions.
- Bone Renaming and Re-parenting: Renames bones to conform with VRChat's standards and reparents them for better control.
- Conversion Tools:
- Model Importing: Supports importing models from various formats, including MMD (MikuMikuDance) and XPS (XNALara).
- Material Conversion: Converts materials and textures to be compatible with Unity, which is used for uploading models to VRChat.
- Utility Features:
- Pose Mode: Allows for easy posing of models for previewing animations and testing rig functionality.
- Avatar Scaling: Provides tools for scaling the avatar to VRChat's height standards.
- Performance Optimization: Includes tools for reducing draw calls and improving overall performance of the model in VRChat.
The CATS addon is widely used by VRChat content creators but also by many regular Blender users who make use of a subset of its features.
The original development of the addon grew stale after the release of Blender 4.0. However a reliable fork is now available. You will find a link to both versions in the beginning of this article