[VRChat] A Wall That Reacts to Music with AudioLink: Glowing on the Bass

You've probably seen worlds where the walls pulse with the music. It's a staple effect in club worlds.

Doing it yourself looks like it starts with audio analysis. In practice, there's a mechanism that takes that whole part off your hands.

It's AudioLink. This article builds one wall panel that glows with the BGM's bass.

What You'll Learn

• The mechanism that turns audio into four numbers
• The shortest route from installation to one panel
• Splitting bands across your decorations
• Where to look when nothing glows

Start from having read materials and textures and placing spatial audio.

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Audio becomes four numbers, distributed

Boiled down, AudioLink does one thing.

It analyzes the playing audio, turns it into four numbers, and distributes them across the world.

The four are bands split by pitch.

Band	What it picks up	What it suits
Bass	Kick, bass	Whole walls, floors, large surfaces
Low Mid	Snare, guitar	Mid-sized decorations
High Mid	Vocals, synths	Thin strips, lines
Treble	Hi-hats, cymbals	Small points, fine details

The receiving side just reads these numbers and changes brightness or color. No audio analysis required.

And the distribution isn't limited. The same numbers reach every material in the room at once. Walls, floors, and signs can each pick whichever band they like.

Three things to do in this article.

1. Add AudioLink to the project
2. Connect an audio source to AudioLink
3. Set the wall's material to glow on Bass

No shader writing. You just fill in fields on a supporting shader.

Hands-On: Build a wall that glows on bass

Put one panel that brightens with the bass into a room with BGM playing.

1. Install AudioLink

Open the project from Creator Companion (VCC) and choose "Manage Project."

Find AudioLink in the package list and add it. If it doesn't appear, register the repository URL from AudioLink's distribution page in VCC and it will.

Return to Unity once added. An AudioLink folder appearing in the Project window means it worked.

2. Place the Prefab and connect the audio source

Prepare the following in the scene.

Name	How to make it, and settings
Bgm	Create Empty with an Audio Source. Play On Awake and Loop on
GlowPanel	3D Object → Quad. At the wall's position. Scale (3, 2, 1)

Put a track with clear bass in Bgm's Audio Source. Something with a strong kick makes the motion easier to see.

Find the AudioLink Prefab in the AudioLink folder and drag it into the scene.

Select the Prefab and drag Bgm into the Audio Source field in the Inspector.

That's the only connection. AudioLink analyzes the audio from whatever Audio Source is specified there.

3. Build the glowing material

Build the material for GlowPanel. There are two routes.

Route 1: your existing shader supports it

Shaders commonly used in VRChat, like lilToon and Poiyomi, have AudioLink fields.

1. Open the AudioLink-related foldout in the material's Inspector
2. Check the box to enable it
3. Set the destination to Emission
4. Set Band to Bass
5. Raise the strength

Route 2: duplicate AudioLink's sample

Without a supporting shader on hand, duplicate a sample material from AudioLink's folder.

1. Right-click the sample material and choose "Duplicate"
2. Name it something like PanelGlow
3. Set Band to Bass
4. Adjust the emission strength

Either route, you're looking at the same things.

Field	Setting
Emission	Enabled
Emission color	Not pure black
Band	Bass
Strength	Not 0

Drag the finished material onto GlowPanel.

4. Confirm

Press Play.

Check	Expected result
BGM is playing	You hear the audio
Look at the panel	Brightness changes with the kick
A quiet section of the track	The panel dims
The chorus	The panel glows strongly

Look at it in a darker room. In a bright room it's hard to tell whether it's glowing.

If it doesn't move, first check whether the AudioLink Prefab has an Audio Source assigned. That omission is the most common cause.

Split the bands

Once one panel glows, next you build the whole room.

Putting everything on Bass means it all lights at the same moment. It's impactful, and monotonous.

Here's the guidance for splitting.

Target	Band to watch	Why
Walls, floors, large surfaces	Bass	It moves slowly and largely, suiting wide areas
Pillars, signs	Low Mid	Mid-scale motion
Line lighting, thin strips	High Mid	It moves finely, suiting thin shapes
Small points, particles	Treble	The finest motion

Large things slowly, small things finely. Keep that mapping and it reads convincingly.

Don't max out every strength either — only the lead. Everything glowing at full leaves nowhere to look.

Common Pitfalls

• Nothing glows at all → No Audio Source is assigned to the AudioLink Prefab
• Audio plays but nothing reacts → The material's AudioLink fields are disabled, or the strength is 0
• It glows only faintly → The Emission color is too dark. Use a brighter color
• Everything moves identically → Everything is watching Bass. Split the bands
• You can't tell the difference in a bright room → Check in a darker room. Emission shows best in the dark
• The shader has no AudioLink fields → Swap to a supporting shader. There's no need to write one

Bonus: Good to Know Up Front

• It reacts to video audio too: AudioLink watches an Audio Source's waveform. Connect a video player's audio and the room pulses with whatever's playing
• It doesn't break in worlds without AudioLink: Supporting shaders draw as ordinary materials when AudioLink isn't present. If it doesn't suit, you can remove it
• Be careful for Quest: Supporting shaders may be unavailable on some devices. If you're building the Android version too, verify with the steps in supporting Quest and phones
• Keep glowing surfaces limited: An entire room glowing tires the eyes. Leaving plenty of calm surfaces and limiting the glow to part of the space feels better
• It's useful all over: Club walls, live venue lighting, rhythm game effects, a gentle pulse in a quiet lounge. Kept subtle, it works in calm spaces too

Summary

AudioLink is a mechanism that turns audio into numbers and distributes them.

• What gets distributed is four band numbers. You don't do the analysis
• Place the Prefab and connect one Audio Source
• Glowing comes from a supporting shader's settings. You don't write it
• Large surfaces on Bass, fine details on Treble

The question to ask while building is: "Does this move large and slow, or small and fine?" That decides which band it watches.

To refine the look further, go to baking lights. To make rendering lighter, go to making rendering lighter.