Shape the
force
that moves.
Draw a spectrum. 32 harmonic bars. That spectrum becomes a repeating waveform — not routed to your speakers, but injected as force into a mass-spring network. The masses respond mechanically. What you hear is Newton's answer to your drawing.
Simple spectra produce pitched tones. Complex spectra drive the masses through chaotic motion. The physics filters, transforms, and surprises. The same spectrum sounds different at every stiffness setting because the mechanical response changes.
This is the excitation chain — the bridge between sculpting timbres and physical modeling. Two instruments fused into one. The sculptor provides the energy. The masses shape the sound.
The additive synthesis engine from the Sculptor generates a periodic waveform from your 32 bins. Instead of routing to the speaker, it becomes a force signal — f(t) — applied to a target mass. The sculpted timbre is the energy source. Complex spectra produce rich, evolving excitations.
The mass network acts as a mechanical filter. Spring stiffness determines resonant frequencies. Damping controls how long energy persists. The excitation spectrum gets reshaped by the physics — some harmonics are amplified at resonance, others are absorbed. The same drawing sounds different on a soft network versus a stiff one.
Choose which mass receives the excitation force. Each mass couples differently to its neighbors through the spring network. Target M0 and masses M1, M3 respond through adjacent springs. The force spread parameter controls bleed — how much force leaks to neighboring masses.
At low stiffness the masses oscillate gently, following the excitation. Increase stiffness past the bifurcation threshold and the nonlinear springs distort the response — the excitation spectrum gets folded, intermodulated, shattered into harmonics that weren't in your drawing. This is where interesting happens.