Several tools claim to offer efficient GLB to VRM conversion. When looking for a method that provides a better conversion:
You converted the file. Now, is it actually better? Run this checklist:
Blender’s VRM exporter cannot create complex physics. Unity (with the UniVRM package) allows you to: convert+glb+to+vrm+better
This is where "better" conversion happens. Install the CATS (Blender Addon) plugin.
Pro Tip: If your GLB had no facial bones, use CATS to auto-generate shape keys for eye blinking and mouth opening. Several tools claim to offer efficient GLB to VRM conversion
Converting GLB to VRM with Improved Fidelity and Compactness
Why this is "better" than web converters? VRoid Mobile was built by pixiv (the creators of VRM). Their algorithm prioritizes morph targets and eye tracking. However, it downsamples textures to 2k and strips custom shaders. Blender’s VRM exporter cannot create complex physics
The Verdict: 7/10 for convenience. 3/10 for texture fidelity.
Best for: Simple humanoid models without complex facial rigging.
Tools: VRoid Mobile (iOS/Android) or Nightily VRM Converter.
VRM relies on blendshapes (also called morph targets or shape keys) for facial expressions: Joy, Angry, Sorrow, Fun, Blink, etc. Most GLB files from hard-surface modeling lack these entirely. "Better" conversion means generating or mapping these facial expressions.