pub const SIGMA_CEILING: f32 = 0.97;Expand description
The ceiling every map’s operator norm is held under (ADR-0075).
A look constant with no principled value, and it is worth being honest
about that. It is far enough below 1.0 that floating-point error cannot
cross it, and it leaves the fern’s largest singular value — 0.851 — about
17 % to grow, which is what vigor has to work with. Whether that is enough
to feel like a surge is a question for the content pass; if it is too tight,
this constant is the lever and widening the parameterization is not.
A preset asking for more vigor than this allows gets silence rather than an
error — the same undiscoverable-ceiling shape presets/README.md already
documents for bloom_threshold and perspective.