GravityField is the law of one well (logarithmic tail, softened core).
Zone.GetForce and GetHeight sum it over the bodies; GetNormal derives from
the force for ship tilt; Flow and Ship read GetForce. Well strength, core
radius and Roche limit are PlanetSettings curves of mass, height
exaggeration K one global. Deletes GravityAcceleration, GravityReferenceRate,
GravityStrength, the PowerPulse well, GetNormal's finite differences and
BodyData.GravityDepthExponent. Settings.asset carries the calibrated curves.
Tests: PotentialOwnerTests, the moon's moon placement, retired keys over every
BodyData type, a body-derived giant sweep. Not yet built or run (verify job
follows); this commit may not build.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
GetOrbitPosition places a parent as a side effect of placing its child, so with a child listed first the parent's previous position was already its new one and its Velocity came out zero. The constructor's unread PreviousPosition write is dropped; the first Update takes it from the placed Position. The velocity test now runs moon-first and planet-first packs over varying dt. Builds not verified yet (verify follows).
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Orbit.Position and PreviousPosition are set from GetOrbitPosition at the pack's
time in the constructor, so wells, lights and poses are valid before the first
Update. AddOrbit and CreateOrbit had no caller. Tests not yet run.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
