cats-blender-plugin VS VRM_IMPORTER_for_Blender

You should use Cats Blender plugin in Blender. The recommended version is Blender 3.5, which you can find in their archives. And dev branch of cats, but I like this fork because keeps the bake tool. You can use Blender 2.8 (the version the latest official release of cats uses).

As for the stretchy-stretch, not sure. But if you use cats in Blender, you could probably automatically fix it. The latest version to use is Blender 3.5 with the Cats dev branch (just grab zip, add that). Though I prefer this fork for 3.5, because it keeps the bake functionality. Or Blender 2.80, if you prefer.

Hi I'm the newbie, I'm a Vtuber trying to animate with my 3dmodel that was created in mind for VSeeFace just for fun and to create some animations to post. I ran into a few problems like Blender not taking the .vrm format but i used a plugin called CATS to get it to import.Ive been trying on my own to animate with the model but doing anything like moving it slows my PC down a ton, I also have a couple concerns like why is there so many bones and colliders.Link to cats (using development version): https://github.com/absolute-quantum/cats-blender-plugin

Decimation of skinned meshes (your Mixamo characters) can be done with various tools. Results will vary. Depends a lot on the topology of the input mesh. Nothing beats proper retopology. There are paid assets on the asset store. https://assetstore.unity.com/?q=mesh%20optimization&orderBy=1 NanoLod is free but can't remember if it does skinned meshes. https://assetstore.unity.com/packages/tools/modeling/nanolod-automatic-lods-193314#reviews More advanced is Simplygon which has a free tier I think. https://documentation.simplygon.com/SimplygonSDK_9.1.27400.0/unity/ My favourite is a blender tool originally intended for VRChat avatars but works on any characters. https://github.com/absolute-quantum/cats-blender-plugin As well as simplifying the mesh data, I would recommend combining the separate parts into a single mesh and texture atlas into only one or two materials (one opposite, one with transparency for hair)

You can download the development branch from github for CATS, it should work with 3.5

I've used Models Resource for finding existing models, and some of them come with proper rigging/skeleton. If you manage to get such a model, you should import it into Blender using CATS plugin and do the necessary tweaks before exporting it as an FBX to then import into Unity. One thing to make sure is that is has all of the proper bones that VRChat needs for the Avatar Descriptor; if it doesn't, these can be added in Blender.

Model Link Ported to blender using Cats Blender Plugin