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VRoid Studio bridge

The VRoid bridge takes a VRoid Studio avatar (.vrm) and produces a Unity-Humanoid-ready prefab with optional VRChat / Modular Avatar integration. The full pipeline runs in ~60 seconds on a warm cache.

Bridge namespace: vroid_* — 95 tools.

What it does​

StepTools involved
1. Import VRM (binary glTF)vroid_import_vrm, asset_import
2. Configure Humanoid rigvroid_humanoid_setup, animation_rig_validate
3. Apply blendshapes (facial)vroid_apply_blendshape, vroid_blendshape_atlas_build
4. Materials → URP/HDRPvroid_materials_convert (handles MToon → URP/HDRP)
5. Optimize meshesmesh_optimize, mesh_merge_static
6. Optionally: Modular Avatar prefabclothing_modular_avatar_install
7. Optionally: VRChat-compatible upload prefabvroid_vrchat_prepare
8. Save final prefabprefab_create, asset_label_add

Prerequisites​

  • VRoid Studio (free) installed locally for editing avatars (Buril does not edit .vroid files — only consumes the exported .vrm).
  • A .vrm file exported from VRoid Studio at the resolution you want. Buril does not re-resolution-scale.
  • For URP/HDRP materials, the corresponding render pipeline package installed in your Unity project.
  • For Modular Avatar integration, the Modular Avatar source is absorbed into Buril — no separate install needed.

Recipe + wizard​

There are two ways to run the pipeline:

A. The chat (one-shot)​

Import Assets/Inbox/Avatar.vrm and run the full VRoid pipeline into Assets/Characters/Avatar.

The vroid-pipeline specialist runs all 8 steps and reports the resulting prefab path.

B. The first-run wizard (interactive)​

Tools → Buril → VRoid Wizard

The wizard walks each step with a preview pane. You pick:

  • Target render pipeline (Built-in / URP / HDRP).
  • Whether to install Modular Avatar wiring.
  • Whether to prepare a VRChat upload pass.
  • Where to save the final prefab.

The wizard generates an agent_team_record trace at the end, so you can re-run the same configuration later via --replay.

Autoimport​

Drop a .vrm into Assets/Buril/VroidInbox/. The autoimport watcher (registered when the bridge installs) detects the new file and triggers the default pipeline automatically. To disable, delete Editor/Buril/Watchers/VroidInbox.cs or set BURIL_VROID_AUTOIMPORT=off.

VRChat workflow​

vroid_vrchat_prepare:

  • Builds the VRC SDK3 component graph (Avatar Descriptor, Pipeline Manager, View Position).
  • Applies the standard VRChat performance preset (PC: Excellent target).
  • Tags blendshapes per VRChat's visemes + eye-look conventions.
  • Saves a final prefab marked VRChat: ready.

VRChat uploads are not done by Buril — open the VRChat SDK panel and upload the prepared prefab manually. Buril gets you to a clean upload-ready state, then hands off.

Modular Avatar workflow​

clothing_modular_avatar_install:

  • Adds a Modular Avatar component graph to the avatar prefab.
  • Wires bones for clothing mounts (BoneProxy, MergeArmature, MeshSettings).
  • Validates against MA's expected structure (no missing pivots, no broken parent chain).

Modular Avatar source is absorbed under MIT — see Third-party licenses for attribution.

Common issues​

SymptomFix
MToon materials look magentaSwitch to URP/HDRP and re-run vroid_materials_convert with target set explicitly.
Humanoid rig fails validationVRoid sometimes exports T-pose with a slight hand offset. Run animation_rig_validate --auto-fix true.
Blendshapes don't fire from animatorThe VRoid blendshape names differ from VRChat visemes. vroid_blendshape_atlas_build adds an alias mapping — ensure it ran.
Mesh is dense (~120k verts)Run mesh_optimize --target_verts 30000 after import. VRoid exports are raw.

Files this bridge touches​

  • Assets/Characters/<name>/ — the final prefab and supporting materials/meshes.
  • Library/BurilCache/vroid/ — intermediate cached blendshape atlases.
  • Assets/Buril/VroidInbox/ — drop zone for autoimport.

Licensing reminder​

VRoid Studio is published by Pixiv. Avatars created in VRoid carry the VRoid character license the creator set when exporting — read it before redistributing. VRoid Hub upload T&Cs are separate from local use. Buril does not modify license metadata embedded in the .vrm.