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Updating Avatar Shaders for Light Volumes

Most of the time, when an avatar is not reacting properly to VRC Light Volumes, the problem is not that the shader is fundamentally unsupported.

The problem is usually one of these:

  • the shader version on the avatar is too old
  • the shader package was updated, but the material is still using an older version path
  • the shader has a feature toggle that still needs to be enabled

This page is here to help users fix that instead of assuming they are stuck on plain light probes forever.

Most common fix

Update the shader, unlock the material if needed, re-upload the avatar, and test it in a real VRC Light Volumes world.

General Update Workflow​

For most avatars, the update process should look like this:

  1. Find the shader currently used by the avatar materials.
  2. Check whether it is on RED_SIM's compatible shader list.
  3. Compare the installed version against the supported since version.
  4. Update the shader from its official source.
  5. Re-open the avatar, verify materials, and re-upload.
  6. Test the avatar in a world that uses VRC Light Volumes.

If the shader supports VRC Light Volumes and the avatar still does not react properly, check the shader's documentation for a Light Volume related toggle or lighting option.

Poiyomi: The Most Important Special Case​

Poiyomi deserves special treatment because a lot of avatars use it, and because users often think they updated it when they actually did not fix the material version problem.

Poiyomi support version​

According to RED_SIM's compatibility list, Poiyomi supports VRC Light Volumes 2.0.0 starting at:

v9.2.67

How to update Poiyomi correctly​

Poiyomi's official docs and repository make a few things very clear:

  • the latest version should be installed from Poiyomi's official VCC / ALCOM / GitHub / BOOTH / Pro channels
  • locked materials may stay stuck or break visually across major upgrades unless they are handled properly
  • Poiyomi materials often need to be unlocked when making changes, then locked again for final upload

The safe workflow is:

  1. Update Poiyomi from the official distribution source.
  2. If the avatar materials are locked, unlock the shader on those materials.
  3. Make sure the material is actually using the latest supported Poiyomi version you installed.
  4. Re-lock the material or let Poiyomi auto-lock during upload.
  5. Re-upload and test in a VRC Light Volumes world.

Why people get stuck on Poiyomi​

Poiyomi includes multiple released versions for backwards compatibility. That is useful, but it also means users can install a newer Poiyomi package while the avatar materials still point at an older material or shader version path.

That is why for Poiyomi, simply installing the latest package is sometimes not enough.

If the avatar still does not react to Light Volumes, unlock the material and verify it is actually using the newest supported Poiyomi shader version available in the project before you upload again.

Official Poiyomi update notes worth remembering​

From Poiyomi's official documentation and repository:

  • VCC updates can be applied from Manage Project
  • manual package installs should delete the old _PoiyomiShaders folder before importing the new package
  • locked materials can get stuck because the shader name changed across upgrades
  • unlocking materials before upgrading helps avoid that problem
  • Poiyomi auto-locks materials during VRChat upload
warning

For Poiyomi avatars, do not assume the package update alone fixed Light Volume support. Unlock the material, verify the shader version, then re-upload.

lilToon and Mochie Notes​

Two other common cases are worth calling out:

  • lilToon is listed as supported from v2.0.0, and its official project provides current releases and package-install methods. If the avatar is on an older lilToon version, update the package first.
  • Mochies Unity Shaders are listed as supported from v1.62.3, and Mochie's official releases explicitly mention Light Volumes support in that release line. If the avatar uses an older release, update from the official GitHub releases and re-import cleanly.

If It Still Looks Wrong​

If the avatar still does not react properly after updating:

  • verify the installed shader version is actually new enough
  • check whether the material is still locked
  • check whether the shader has a Light Volumes or lighting-related toggle
  • make sure you are testing in a world that really uses VRC Light Volumes
  • compare in more than one test world before assuming the shader is broken

Advice for Avatar Creators​

If you make or maintain avatars:

  • prefer shaders that already support VRC Light Volumes
  • keep those shaders updated
  • test in actual Light Volume worlds instead of assuming support is active
  • check shader-specific toggles if the package is updated but the avatar still looks wrong

See Shader Support for Light Volumes for the reference list.