Drift-time peaks used to rail into the hard elevation clamp and flatten into a
9000 m plateau (the clamp lived in step(), erode() AND hydrology(), so erosion
re-flattened them every tick). Replace the hard ceiling with a probabilistic
soft cap: above peakSoftCapStart (7000 m) the chance a tick's uplift "takes"
falls linearly to 0 at peakSoftCapEnd (12000 m); a lost grow roll forfeits the
uplift and shaves a random 0..peakFailDrop (200 m) off. Peaks now spread smoothly
across a height band (strong orogeny reaches ~10-11 km, most cluster lower) with
zero cells pinned at the ceiling.
- The roll is a pure hash of (cellIndex, erodeIter, seed): never touches
rngState, bit-identical across OpenMP thread counts, and since erodeIter is
saved (step/erode run 1:1 in drift) F5/F9 resumes bit-identical -- no save bump.
- Drift-only (gated on Planet::drifting) so Phase-1 forming still auto-settles.
- The hard clamp's upper bound now tracks peakSoftCapEnd in all three places
(step/erode/hydrology); lower -11000 m unchanged.
- New planet.cfg knobs peakSoftCapStart / peakSoftCapEnd / peakFailDrop with
validation (+ start < end cross-rule). Docs updated (CLAUDE.md, BUILD.md).
Verified headless: smooth 8.5->10.5 km taper, 0 pinned, determinism + exact
resume intact, test_logic + test_biota pass, full app builds clean.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
C++/raylib semi-realistic fantasy/sci-fi planet generator on a fixed icosphere
grid (Eulerian: properties flow over fixed cells). World-creation stages:
tectonics, continental drift & erosion, hydrology (rivers/lakes), climate
(temperature + orographic precipitation), and biome classification. Engine in
src/sim (raylib-free, headless-testable), viewer in src/render. See CLAUDE.md
and docs/ (design-notes.md, fauna-flora-plan.md = next step).
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
