Modifiers & Modulation

Modifiers are special nodes that generate control signals to animate parameters throughout your plugin. They add movement, expression, and dynamics to static settings.

The LFO Modifier

Currently, Plugin Builder provides the LFO (Low Frequency Oscillator) modifier.

The LFO generates a repeating waveform that can be routed to any parameter:

Parameter	Range	Description
Rate	0-20Hz	Oscillation speed
Depth	0-100%	Output amplitude
Offset	-100% to +100%	DC offset
Shape	Sine, Triangle, Saw, Square	Waveform

Modulation Routing

Connecting Modifiers to Parameters

Method 1: Direct Drag

1. Add an LFO modifier to your graph
2. Locate the Mod output port (purple)
3. Drag from Mod output to a parameter knob in the target node’s Inspector
4. A modulation connection is created

Method 2: Inspector Binding

1. Select the target node
2. In the Inspector, find the parameter to modulate
3. Click the Mod button next to the parameter
4. Select the LFO from the list

Modulation Amount

Each modulated parameter has a Mod Amount control:

• 0%: No modulation effect
• 50%: Half of LFO range applied
• 100%: Full LFO range applied
• Negative values: Inverted modulation

The formula:

final_value = base_value + (lfo_output × mod_amount × parameter_range)

Modulation Chains

LFO modifiers have both Mod In and Mod Out ports, enabling chaining:

LFO 1 → LFO 2 (modulates LFO 2's rate) → Target Parameter

This creates complex, evolving modulation patterns.

Using Link Nodes for Modulation

The Link Node can route modulation signals to multiple destinations with conditional logic:

LFO → Link Node (All mode) → Param A
                          → Param B
                          → Param C

Or use Single/Mask modes for selective routing.

Shader Modulation

Modifiers can drive visual properties in your Faceplate UI, not just audio parameters.

Setting Up Shader Modulation

1. Select a UI component on the Faceplate
2. In the Inspector, find Shader Properties
3. Click Add Mod Source on a property (e.g., color, opacity, scale)
4. Select the LFO modifier
5. Set the modulation amount

Modulatable Shader Properties

Property	Effect
Color	Animate hue, saturation, brightness
Opacity	Fade in/out
Scale	Pulsing size
Rotation	Spinning animation
Position Offset	Movement
Glow	Pulsing glow intensity

Example: Pulsing Button

1. Add an LFO (Rate: 2Hz, Shape: Sine)
2. Select a button on the Faceplate
3. Bind LFO to the button’s Glow property
4. Set Mod Amount to 50%
5. The button now pulses with the LFO

Common Modulation Patterns

Vibrato

• Target: Pitch parameter
• Rate: 5-6Hz
• Depth: 10-20%
• Shape: Sine

Tremolo

• Target: Volume parameter
• Rate: 4-8Hz
• Depth: 50-100%
• Shape: Sine

Auto-Pan

• Target: Pan parameter
• Rate: 0.5-2Hz
• Depth: 100%
• Shape: Sine

Filter Sweep

• Target: EQ frequency
• Rate: 0.1-0.5Hz
• Depth: 50%
• Shape: Triangle

Wobble Bass

• Target: Filter cutoff
• Rate: 1-4Hz (tempo synced)
• Depth: 80%
• Shape: Sine or Triangle

Tips

• Start with subtle modulation and increase gradually
• Use Offset to shift the modulation range up or down
• Combine multiple LFOs at different rates for organic movement
• Sync LFO rates to musical divisions when appropriate
• Visual modulation (shaders) can indicate audio modulation state