Procedural Geometry Controls: MIDI-Driven Arc Systems

Arc Animation Architecture

The implementation centers on a dual-lag chain driving Carve SOP parameters. The first lag operator establishes the leading edge response, while a second lag trails behind with longer decay. Math CHOPs scale and offset the lag outputs before clamping to the 0-1 range required by Carve's domain parameters. The configuration produces a controlled three-quarter circle sweep—large enough for visual clarity while maintaining headroom for velocity modulation.

Draw speed derives from lag coefficient adjustment. Lower values yield faster response; higher values extend the sweep duration. Optional low-pass filtering smooths abrupt transitions when needed.

Velocity-Sensitive Variants

Velocity normalization feeds a multiplier stage that maps MIDI input intensity to arc length. Harder strikes expand the sweep range proportionally. The system maintains musical correlation: dynamic performance produces dynamic visuals.

Concentric ring variants duplicate the lag/math chain with staggered Carve offsets. Each ring maintains independent temporal behavior while sharing the same trigger source. The result: expanding waves of geometry radiating from origin on each note event.

SOP Pool Randomization

A reusable selection system routes a single MIDI impulse through:

• Math CHOP (random value generation)
• Quantize CHOP (discrete integer conversion)
• Limit CHOP (constraint to pool size)
• Switch SOP (indexed geometry selection)

The wiring enables non-deterministic selection from a pool of static and procedural geometries without manual intervention. Adding new variants requires only expanding the Switch SOP input count.

System Integration

The animated arc preset shares the established CHOP structure: select → lag/filter → math → limit → export. This pattern proved compatible with existing line-animation pathways, confirming the architecture's modularity. Each geometry type can implement the same signal flow with type-specific parameter mapping.

Reference networks, Carve configurations, and implementation details are documented in ADDITIONAL_SUGGESTIONS.md for rollout to additional primitive types.

Technical Notes

• Carve SOP instances remain efficient at reasonable curve resolutions.
• Multiple concurrent lag chains scale linearly with geometry complexity.
• Switch SOP branching requires verification that unused inputs don't cook unnecessarily.
• Velocity normalization ranges may require per-instrument calibration.

The modular approach establishes a reusable framework: MIDI input, CHOP processing chain, SOP parameter driving. Future geometry types inherit the architecture with minimal rewiring.

Process demonstration