The base term in a mapping transfer function is the visual floor at silence — it must produce an intentional frame when a.fft is zero

When the music drops out entirely, a.fft[0..3] approaches zero. A mapping of the form base + gain · a.fft[i] will reduce to its base value. If base = 0, the parameter hits its minimum — which may be black screen, blown-out white, or zero rotation. These are usually unintentional and read as a broken visual rather than a purposeful drop. Choosing a positive base guarantees a visible, readable frame even at silence. A mapping that produces silence=black is only acceptable when that is deliberately the intended behavior.

Examples

() => 0 + a.fft[0] * 3.1 — at silence the oscillator brightness is 0 (black). () => 0.6 + a.fft[0] * 2.5 — at silence brightness is 0.6 (dim but visible), which the seed uses by design.

Assessment

A brightness mapping uses () => a.fft[0] * 3. During a breakdown the frame goes black. Diagnose the issue and propose two different fixes.