Optional ReadonlyminDistance floor in world units, default DEFAULT_VORTEX_MIN_DISTANCE,
measured perpendicular to the axis. Must be finite and > 0.
Caps the tangential acceleration at |strength| / minDistance
(100 · |strength| at the default). Same advice as
RadialFieldOptions.minDistance: raise it to the visible radius of
the vortex core.
Options of vortexField.