Resonant Drum Field · A/B controlled comparison →

What this demonstrates

• The adapted Countercurrent linear shallow-water / C2-Wendland reciprocal coupling (Apache-2.0) recontextualized as a 7-pad visual instrument, extended to N bodies and a circular reflecting basin.
• The controlled page records a fixed-state visual and simulated-state difference when reciprocal water→pad feedback is enabled. Live panes are exploratory and do not share a browser clock.
• CPU tests: N-body energy/volume conservation, pad-to-pad reciprocity, mutant-must-fail checks.

What this does not demonstrate

• That reused code is universally better, faster, or necessary.
• Frame-time measurements cover only the recorded browser and hardware configuration.
• The upstream GPU compute path (the physics here runs on the CPU port; WebGPU is used for rendering).
• Physical accuracy beyond the linear shallow-water model.

Each pane has visible pause, reset, autoplay, scripted-sequence and touch-pad controls. The page is a visual pad simulation; it has no audio output. MIDI is optional, experimental, and untested with physical devices. Evidence · Apache licence · NOTICE · Three.js MIT notice.