My Custom Base (MCB) by Enzo

1.12.7 — 2026-10-11

Fix Extraction failed: Could not find a part of the path when downloading a version into a project at an ordinary path (about 40 characters, e.g. D:\VRChat Stuff\Unity Projects\Ultinova): the download’s staging folder added a 42-character suffix to an already long version folder, past the 259 characters Unity can use on Windows. Staging and replaced folders now add 18 characters at most (Orbiters Toolkit 0.3.21).
Hashes in MCB’s local names are cut to 16 hex digits (MCBUtils.PathHash): version folders (u1.0.0d1.0.0-60281cc859dc167a, was u1.0.0d1.0.0-source-<64 digits>), generated advanced meshes and their humanoid Avatars, refit caches, and the files a build makes for its other originals. Ultinova’s longest version file now needs 128 characters past the project folder instead of 188. Nothing is migrated: a version downloaded with an earlier MCB is downloaded again when applied (an avatar using it offers Download and Update to the same version once), saved versions exported before are not recognised, and refits saved for versions that are not applied are not found again.
Before downloading, MCB checks that the version’s files fit at the project’s location; if not, it says how many characters shorter the project’s folder path must be instead of failing after the download.
A saved version exported from a creator’s build of several originals installs offline for each of them. The server’s entry used to win over the local copy of a non-primary original and pointed at that original’s own folder, so MCB downloaded it again. A published version whose local build no longer holds the original now downloads the original’s own copy instead of reporting “This local build is incomplete”.
Exporting a saved version keeps the version folder’s own version.json. It was rewritten with the row’s metadata: exporting one original’s view of a creator’s build replaced the build’s metadata, hid the build from MCB and made the package unrecognisable on import.
Applying or resetting no longer logs “Shader … is not supported” errors for avatars whose shader MCB never puts veins on (lilToon, a missing shader): there is nothing of MCB’s to remove there.
Advanced versions use the avatar’s own copy of their original as the pose source when it sits at another path (a moved or renamed package folder). For another original (Novabeast V1.2 under a version built on V1.0) the payload’s own skeleton stays the pose, now an information line instead of two warnings on every apply.
Restoring pre-MCB backups stages its copies under hidden names (~), so Unity no longer imports them, and leaves stray .meta files, during the restore’s refresh. The original-base backup’s temporary copy has a short name too.
Requires Orbiters Toolkit 0.3.21.

1.12.6 — 2026-10-10

The sliders MCB adds to the menu get Orbiters’ gauge icon (OrbitersMenuIcons.Slider, from Orbiters Toolkit).

1.12.5 — 2026-10-09

The account row and its sign-in buttons are Orbiters Toolkit’s (OrbitersAccountElement), as in My Avatar: MCB’s own account and sign-in modules are gone. Signing out still asks first. The sign-in buttons now show in the account row under the banner instead of a card above the gallery. MCB still reads the signed-in creator’s details (whether Orbiters trusts them, for a new custom base’s protection settings).
Source FBX files are taken from a .unitypackage through Orbiters Toolkit’s UnityPackageReader, the one reader every Orbiters tool shares: the package’s structure is checked as strictly as before an import (tar checksums, record names, one GUID per path), and each FBX is hashed while it is extracted instead of being read again afterwards.
The server address comes only from Orbiters Toolkit: MCBUtils’ unused SERVER_BASE_URL, API_BASE_URL, TOKEN_ENDPOINT and its own copy of the development switch’s key are gone.
The bone position offsets find the avatar’s MCB component with the blendshape links’ lookup instead of a copy of it; the unused BlendShapeLinkService.ApplyVersionLinks is gone.
Requires Orbiters Toolkit 0.3.19.

1.12.4 — 2026-10-08

Fix avatars placed under another object in the scene (an “Avatars” folder object) losing their armature and meshes on version apply or reset: the avatar root is now the object with the avatar descriptor, never the top of the scene.
Fix switching from one FBX version to another leaving models the first one patched and the next one does not (a head FBX patched by A only kept A’s bytes, and a later reset missed it): those models get their original bytes and import settings back first.
Reset puts back each model’s own import settings, kept (as <model>.fbx.originalimport~) before a version first gave it its own Avatar. Models the version never touched (hair, props, generic models) are left as they are; before, every base FBX was switched to the version folder’s humanoid Avatar.
Fix HDiff versions failing to apply, and creators’ patches falling back to full XOR files, when the project or avatar folder has non-ASCII characters (Japanese Booth folders, accented user names): paths reach HDiff as UTF-8.
Original-base backups are written to a temporary file, verified and then moved into place; a reset refuses a backup whose bytes differ from the ones recorded when it was made, and a damaged cached original key is replaced. When the base package was re-imported while a version was applied, the newly imported original replaces the stale backup (the old one is kept aside) instead of being overwritten by it.
Fix “default avatar.asset” not built for a version when the creator’s FBX had an original-base backup.
Applied advanced versions stay recognised after a Unity editor upgrade (their shared meshes sit in a folder named after the editor version they were made with).
Delete local files refuses while the version is applied or its files are used (scenes, assets, a model’s Avatar).
Plain advanced versions made of several FBX models reset every model their renderers come from, not only the first.
A replaced renderer the user deleted or renamed no longer blocks every reset or switch of an XOR advanced version: the others are restored and a “Renderers skipped” warning names it (as plain versions already did).
Creators can no longer build an XOR advanced version while their base FBX is not its original: reset it first.
Reset and Clear cache remove the generated advanced meshes and humanoid Avatars nothing uses any more (decrypted meshes no longer stay in the project); those a version switch’s Undo still needs are kept.
Undoing a version switch older than the last five, whose files MCB no longer keeps, leaves the files as they are and says so instead of silently restoring only the scene.
Custom veins removal only takes off MCB’s own veins texture and the keywords and toggles MCB switched on: a detail normal map, _NORMALMAP or USE_NORMAL_MAPS set by the user or My Avatar stays.
Version switches wait while a refit runs on the avatar (My Avatar or the ReFit panel). A fit taken back in any tool stays taken back after switching versions, and only fits made for a version are saved with it.
Mode locks run before the clothing links at upload, so refitted clothing, Follow Body Blendshapes and accessories take the locked values too; a mode that overrides animations a later build step added (face tracking) logs a warning.
Version downloads interrupted by a script reload no longer leave their files in the system temp folder.
The version list is read from the cache while a version is applied (it was always fetched again, and empty offline).
Version compare checks the original model before decoding and the decoded model against its hash.
The MCB build step also finds the custom base component on a child of the avatar. The live animator controller no longer picks My Avatar’s face tracking test copy.
Requires Orbiters Toolkit 0.3.18.

1.12.3 — 2026-10-07

Fix legs folded inward in VRChat on versions exported from a posed armature (Ultirex 5.1, whose model has its legs spread 26° in a star pose): the avatar’s humanoid definition now rests at the pose its meshes are bound in, which is where applying the version puts the limbs, instead of the model’s exported pose. Partial meshes (feathers) no longer decide it: the payload whose meshes weigh on the most humanoid bones defines the avatar. Avatars get the corrected definition at their next upload or version apply.
Fix eyes that move the wrong blendshapes in VRChat after a version changed the face mesh: the avatar descriptor’s eyelid blendshapes (blink, looking up, looking down) are indices into the mesh, and Ultirex’s mesh has “Throat” and “TailSkinny” where Rexouium had “LookUp” and “LookDown”. Applying or resetting a version now keeps them on the same shapes by name (a shape the new mesh lacks is turned off). Avatars that already have a version applied: apply it again.
Fix twisted feet in VRChat on versions whose model rolled bones the base’s animations rotate (Ultirex 5.1: its toes rest up to 180° turned from Rexouium’s, so the toe curl of Rexouium and of the Ultirex logic turned the paws over). At upload, rotation animations written for the original base model (the base FBX with the avatar’s skeleton) turn each bone the same way from its rest pose on the version’s skeleton. Animations made for the version stay as they are.
Fix a prop’s model taken for the avatar’s base model: Adjerry91’s face tracking template adds a debug panel with its own FBX, and the detected base FBX files listed it first, so versions could treat it as the model they apply to and the upload stripped its blendshapes. Detection now lists the model with the avatar’s skeleton first (the FBX with the most of the avatar’s bones, then the one its meshes are skinned to) and leaves out model files with none of them (bone-less panels, static props). Avatars made of several models keep every model that carries the skeleton.
Physic and Squishy chains are tuned per version: a version can store its PhysBone pull, momentum (spring), stiffness, gravity, immobile and angle limits (physicSettings, squishySettings in its customization). Versions that store none keep the values used so far.
The About window is now the Toolkit’s shared one (requires Orbiters Toolkit 0.3.17).

1.12.2 — 2026-10-07

Fix “Unsupported conversion of vertex data (format 0 to 4, dimensions 4 to 4)” in builds of versions with twisting bones (Ultirex): Unity logged it when a twist gave a vertex more than four bone influences. Both twists were applied already; the build now writes the weights without the error.
XMuscles: undoing Build rig on this avatar removes its contacts and constraints cleanly; Unity no longer warns that a component “had become dangling during an undo operation”.
Faster version list: the applied version is worked out once when the avatar’s meshes or versions change, not for every row on every refresh, and a refresh adds an undo step or an unsaved change only when MCB’s state actually changed. Hidden MCB inspectors no longer ask the server for the account state.
Quieter Console: the apply, native mesh and dynamic normals timings now follow Advanced Options › Log in Console (off by default), and with it on, cache hits, account refreshes and version-state checks are no longer logged on every refresh. Warnings and errors are unchanged.
Fix the wording of the message shown when you do not own the MCB.

1.12.1 — 2026-10-06

Unencrypted versions keep the original base’s pose: switching a T-posed Rexouium to Ultirex 5.1 no longer leaves it in the star pose of the Ultirex FBX. The arms, hands, fingers, legs and feet point like the original base model; bone lengths, hips, spine and head stay the version’s.
XMuscles: Build rig on this avatar places each contact where Blender measured it (XMuscle Orbit Helper API 2): a receiver and sender along the muscle’s stretch, and for twisting muscles a receiver on a pivot an Aim constraint keeps along the twisting bone, so it reads the twist alone (2D blend tree). Exports from another helper API are not stored.
Requires Orbiters Toolkit 0.3.14.

1.12.0 — 2026-10-05

Physic: creators name a version’s secondary-motion bones with “physic” and turn on Support physic in the version form. Users switch Physic on in the version options (off by default). On, the build gives the chains always-on PhysBones, one per parent bone, that every player simulates; off, the build removes those bones and moves their weights to the parent.
Squishy interaction, the same way: bones named with “interaction” (a chain of two) and Support squishy in the version form; on, players’ hands squash them and they spring back (PhysBone squish with collision), off, the build removes them.
The parameter graph of the Sliders card is gone: XRay Gizmos 0.2.8 shows the avatar budget over the Scene view, with the custom base’s share including the PhysBones its build adds and the bones it removes.
Modes are folded by default in the version form.
The avatar’s own animations keep working on bones a version moves to another parent: the build copy’s controllers follow the moved bones.
Authoring drafts can set the realistic material suggestion.
Fix hidden MCB editors left by interrupted operations raising errors after every script reload.
Fix versions with twisting bones uploading without any mesh (Ultirex 5.0.1 was invisible to everyone): the build copied every mesh that listed the twisted bone, in memory, after VRCFury had saved its files, and the SDK’s save of the avatar dropped them. Only meshes weighted to the bone are copied now, once for all its twists, and the build saves them (Orbiters Toolkit 0.3.13).
Authoring drafts build with their own source and custom models, also on an avatar that has a version applied.
Uploads leave out the custom base’s unused blendshapes: the ones no animation, viseme, eyelid or MMD dance uses are removed from its meshes, and one set to a weight is baked in. Ultirex went from 697 MB (over VRChat’s 500 MB limit) to 266 MB uncompressed, 106 MB to download. Play mode keeps every shape.
About credits Prefabulous Universal (MIT), which the twisting bones are adapted from.
Requires Orbiters Toolkit 0.3.13.

1.11.1 — 2026-10-05

The version timeline, gallery cards, safe archive extraction, package hashing, content trust prompts and uploads now come from Orbiters Toolkit 0.3.12, shared with My Avatar’s asset gallery. No change in behaviour intended.

1.11.0 — 2026-10-05

Protection belongs to the custom base asset: trusted creators can verify a Discord role and publish one unencrypted package for every original base, with Discord role access managed from Create custom base and the asset’s Edit panel. Requires the matching Orbiters backend.
Modes replace genres: pick-one and combinable categories with blendshape, object and animation rules, a new Modes card for users, and choices remembered per asset (cleared when returning to the original base).
Material slots follow their names across original layouts, with hidden original pieces, fallback materials and a folded summary in the creator form.
Fix stretched necks and heads after a version moved bones: Avatar assignment and rebinds keep the version’s skeleton pose.
Reset and version switches restore the original FBX hierarchy and pose, ignore same-named logic objects, and keep the avatar’s own original model.
Custom veins apply to and are removed from every material instantly; custom base blendshape values are remembered across a reset.
Differences viewer: realistic distances when a version splits meshes, original materials in their slot order without version veins.
ReFit no longer lists meshes the applied version adds; Blendshapes appear above Sliders; the base row names the original base.

1.10.4 — 2026-10-03

Generate and reuse the native custom base humanoid definition for preview, Play Mode and avatar upload, preventing repeated armature corrections.
Preserve clothing placement in mesh comparison and reuse prepared original-body data for ReFit.
Fix player compilation of the embedded Blender addon and keep the MCB editor assembly out of player builds.

UI Toolkit migration

MCB editor UI is transitioning to Unity UI Toolkit with the shared styled surfaces used by the gallery and account modules. New UI elements and changes to existing UI should be built with UI Toolkit and the package USS style sheets instead of adding new IMGUI blocks.

About and third-party notices

About in the bottom toolbar (next to Advanced Options and Blendshape Links) shows MCB’s version and license and the third-party software it ships with (HDiffPatch with libdivsufsort, CocoTools, YUCP Dev Tools, Prefabulous Universal, Zstandard, zlib, bzip2, the LZMA SDK and LZ4), each with its license. The texts live in Editor/Plugins/Hdiff/THIRD_PARTY_NOTICES.md.

See a version’s differences

The expanded card of a version that ships meshes shows Mesh updated · See differences. It opens a window with the avatar turning in 3D, before and after the version, so creators see what it does to their avatar before applying it:

Slider wipes between before and after with a handle, Side by side turns both together, Overlay shows the version with its former shape as an x-ray ghost. Holding Space shows the before side.
Changes makes the surface that moves glow, from amber (a little) to magenta (the most); Clay shows the shape alone; Textured uses the avatar’s own materials, each on the submesh of its slot name (MaterialSlotNames), whatever submesh order each model has. The clothes button adds the avatar’s other renderers.
It compares the version with the version before it in its history (the parent its creator chose, else the highest published version below it for the same original), or with the original base for its first version. Original and your avatar now are offered too only when they show other meshes: the avatar now when it has another version or customization. Parts are shown with the renderer’s blendshape values, and each version’s new blendshapes at the value its creator chose.
The list of meshes that change flies the camera to each change; blendshapes added, reshaped or removed are listed.
Apply goes through the usual confirmation. The versions it reads are downloaded first when needed; when the version before cannot be downloaded or read, the original takes its place and the window says why.

Reading changes nothing in the project: FBX replacements are decoded in memory (HDiff through a temporary file in Library/MCB/HdiffTemp), advanced meshes are decrypted and parsed in memory (or read from the cache an earlier apply left), and the models are read with Toolkit’s FbxReader. VersionActions.ResolveModelPatches locates a downloaded version’s patches without creating backups; VersionMeshComparison pairs them with the avatar’s renderers and measures the change with Toolkit’s MeshComparison.

Small accessories on the body (beta)

Advanced Options › Blendshape processing › Keep Small Accessories On The Body (beta) adds Toolkit’s Follow Body Blendshapes to the avatar root: piercings, studs and other small rigid accessories on the skin move and tilt with the body’s blendshapes (muscles, versions) at upload and in Play Mode.

Banners

The Orbiters server applies the banner effect (blur and fade toward #303030 over the lower third, the same for web and Unity uploads). The Photoshoot therefore uploads the banner as rendered and shows it with the effect applied locally (Toolkit’s PhotoshootService.ApplyBannerEffect), then the server’s image once the upload returns. This needs a server with the banner pipeline (asset field mcbBannerEffectVersion).

XMuscles (experimental)

Correctives baked with XMuscles in Blender (XMuscle Orbit Helper) come with each Magic Sync export (manifest.xmuscle) and are kept on the custom base per exported mesh (MuscleCorrectiveStore). The Creator panel shows them with their contact cost; Build rig on this avatar (MuscleDriverGenerator) turns each sensor the bake measured (XMuscle Orbit Helper API 2) into a proximity receiver and a point sender where Blender measured them: the muscle’s stretch, from its origin to its insertion, and for a muscle whose drivers read a twist, a receiver on a pivot that a VRC Aim constraint keeps along the twisting bone (up held by its parent), so it reads the twist alone. A 1D blend tree (2D Freeform Cartesian with a twist) puts each corrective fully on at the readings its baked distances give, inside one Direct blend tree, with a VRCFury Full Controller. Contacts run on every client and scale with the avatar; a VRC Raycast would only hit the wearer’s own colliders on the wearer’s client (and colliders are PC only), so others would not see the muscles. Exports from another XMuscle Orbit Helper API are not stored. Publishing the rig with a version waits for the prototype check in Gesture Manager and VRChat.

Custom base FBX backup invariant

MCB custom base versions are applied over the original/default base FBX. If the default base is A and custom bases are B or C, then *.fbx.originalbase (next to the FBX) is always the preserved copy of A.

Applying a custom FBX or version creates *.fbx.originalbase only when it is missing.
Existing *.fbx.originalbase files must not be overwritten, deleted, or moved during apply/reset flows.
Resetting to Base Default copies *.fbx.originalbase back over *.fbx while keeping *.fbx.originalbase in place.
The only valid state without *.fbx.originalbase is the untouched default-base state where *.fbx is already A.
XOR .bin patches are computed against A, so version switching depends on *.fbx.originalbase remaining the original default source.

Editor health checks

MCB includes deterministic editor health checks for risky apply/reset behavior. They are menu-driven checks, not Unity Test Runner edit-mode tests, so they are meant to stay fast enough to run during local development.

Run all deterministic checks from Unity:

Open Tools > My Custom Base (MCB) > Health Checks.
Click All Deterministic.
Check the Console if the dialog reports a failure.

Individual checks are also available in the same menu:

Native Mesh Payload
Version Apply Reset Invariants

For batch-mode validation, run Unity with MCBEditorHealthChecks.RunAllOrThrow:

& "C:\Program Files\Unity\Hub\Editor\2022.3.22f1\Editor\Unity.exe" `
  -batchmode `
  -quit `
  -projectPath "H:\metaverse\unity projects\MCB Test" `
  -executeMethod MCBEditorHealthChecks.RunAllOrThrow `
  -logFile "Logs\mcb-health-checks.log"

Run these checks when touching version apply/reset code, FBX backup handling, native mesh payloads, advanced mesh paths, dynamic normals, material mutations, slider creation, blendshape preservation, or applied-version caches.

Testing SSL failures on Windows

The easiest way to test MCB’s connectivity failure UI is now built into the package.

Open an avatar with the My Custom Base component.
Enable Advanced Mode.
In Connectivity Simulation, set API simulation to:
- SSL Failure to force requests to https://wrong.host.badssl.com
- Transport Failure to force requests to https://127.0.0.1:1
Click Retry connectivity check or reopen the inspector.
Optionally click Open connectivity tests to run the standalone diagnostics window against the simulated target.

SSL Failure is the fast path if you specifically want certificate validation errors. Transport Failure is useful when you only want to verify the “cannot connect” report UI.

Turn API simulation back to Off when you want the package to use the real api.orbiters.cc / dev.api.orbiters.cc endpoints again.

Manual fallback

If you still want to force a real local hostname mismatch on Windows outside the built-in simulation, the reliable manual approach is:

Map api.orbiters.cc or dev.api.orbiters.cc to 127.0.0.1 in hosts.
Run a local HTTPS listener on port 443.
Present a certificate for a different hostname, such as localhost.

That will produce a genuine TLS hostname/certificate error for the real MCB host names.