Feature Discussion: MIDI Control Change (CC) Support for Continuous Parameter Control

[aagentah]

A question came up about adding MIDI Control Change (CC) support to nw_wrld, and I wanted to open this up for discussion before diving into implementation. This would be a significant architectural change, so I'd like to hear from the community about whether this is something you'd actually use.

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What's Being Proposed

Right now, nw_wrld is built around a trigger-based system. When you hit a MIDI note (or send an OSC message), it fires a channel, which executes methods with pre-configured parameter values. Everything is discrete: you trigger something, and it happens with the parameters you've set up in the dashboard.

What's being requested is support for continuous control via MIDI CC messages. This would allow you to:

• Map hardware knobs/faders to method parameters
• Modulate values in real-time during a performance
• Control things like color, size, speed, position, etc. continuously rather than through discrete triggers

Think of it like the difference between triggering a visual effect with a drum pad vs. tweening a parameter with a knob.

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Current Architecture

The existing system works like this:

1. Configuration Phase: In the dashboard, you configure each channel with specific methods and parameter values (e.g., color: #FF0000, duration: 2000)
2. Trigger Phase: A MIDI note or OSC message triggers the channel
3. Execution Phase: The pre-configured methods execute with their static parameter values

This is all handled through InputManager.js, which currently only listens for noteon events on specific MIDI channels:

input.addListener("noteon", (e) => {
  const note = e.note.number;
  const channel = e.message.channel;
  const velocity = midiConfig.velocitySensitive ? e.velocity : 127;
  // ... routing logic
});

There's no listener for controlchange events, and there's no mechanism to dynamically update parameter values after methods have been configured.

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What Would Need to Change

To support MIDI CC, we'd need to implement:

1. CC Message Handling: Add controlchange event listeners in InputManager.js alongside the existing noteon listeners

2. Parameter Binding Layer: Create a system to map CC controllers to method parameters. This would need:

   • A UI for mapping CC numbers to specific parameters
   • A data structure to store these mappings (likely in userData.json)
   • Value scaling logic (CC values are 0-127, but parameters might need different ranges)

3. Real-Time Parameter Updates: Modify the method execution flow in Projector.js to support two modes:

   • Trigger-based (current): Execute method with pre-configured static values
   • Continuous (new): Execute method with dynamically updated values from CC messages

4. Method Categorization: Potentially distinguish between methods that make sense for continuous control vs. discrete triggering. Some examples:

   • Good for CC: color, opacity, scale, rotation, zoomLevel, cameraSpeed
   • Less useful for CC: show, hide, clearAll, viewDirection (discrete states)

5. Starter Module Updates: Update existing modules to handle continuous parameter updates gracefully (right now they assume parameters are set once per trigger)

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Two Possible Approaches

Option A: Hybrid System

• Keep trigger-based as the default
• Add optional CC bindings per parameter
• When a CC binding exists, that parameter gets real-time updates instead of using the configured value
• Pro: Flexible, backward compatible
• Con: More complex UI and data model

Option B: Separate "Continuous Control" Mode

• Methods can be marked as trigger-based or continuous
• Continuous methods live in a separate section of the UI
• Pro: Clear separation, simpler mental model
• Con: More overhead for module developers, duplicated effort

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Examples of What This Would Enable

Example 1: Live Color Tweening

• Map CC 1 (mod wheel) to the hue parameter of a color method
• As you move the mod wheel, the visual's color shifts in real-time
• Currently: You'd need to trigger multiple channels with different color values

Example 2: Dynamic Camera Control

• Map CC 2 to zoomLevel
• Map CC 3 to cameraSpeed
• Control the camera zoom and movement speed with faders during a performance
• Currently: You'd need to trigger methods repeatedly with different values

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My Take

I've always preferred trigger-based systems because they're simpler and encourage more deliberate compositional choices. With that said, I can absolutely see the value for live performance; especially if you're coming from TouchDesigner or other VJ tools where continuous control is standard.

This is a reasonably large feature that would touch multiple parts of the codebase. I'd want to make sure it's something people would actually use. If enough people are interested, we can prioritise it. If not, we can keep the system trigger-based and focus on stabilisation and other features.

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Opening this Poll for both discussion and as a decision.

[gorhgorh]

i just made https://fun.catsandsolenoids.eu/ as i wanted to explore shaders + knobs, authorise midi, type "c" for config and select an interface click learn / configure some midi cc and move things !
That really make me wish for cc and / or scheduled interpolations between values

[gorhgorh]

another idea i want to toy with would be ... lfo, we can get the clock via midi and beat synced lfo with up / low limit would be nice to have to animate parameters, I'll probably have a round of test in my fun playground, and will propose things when i have a state i'm happy with.
This is now in the fun playground as a very basic feature, next step would be to have it beat synced, btw nw_world could easily get a clock if sent via midi, isn't it ?

[gorhgorh]

well this is WAY too much fun, I made an alternative loader / controller for nw_wrld module and I have to say that i'm now missing them in the real nw_wrld :)

demo here https://fun.catsandsolenoids.eu/particles/?module=fragment-shader