Optional ReadonlyenabledWhen false, no ring buffer is allocated. Default true when trail is set.
Optional ReadonlylengthNumber of position samples per particle (≥ 2). Default DEFAULT_TRAIL_LENGTH.
Optional ReadonlyminMinimum distance between consecutive samples. 0 records every step.
Default DEFAULT_TRAIL_MIN_DISTANCE.
Optional ReadonlytailTail width as a fraction of the head width, in [0, 1]. Default
DEFAULT_TRAIL_TAIL_WIDTH_FACTOR (ribbon tapers to zero).
Optional ReadonlywidthRibbon half-width at the particle head, in world units. When omitted, each segment uses half the particle's current drawn size.
§36 trail options, CPU simulation tier.
Omit
trailentirely (or setenabled: false) for no history. GPU simulation refuses trails for the same reason it refuses §27 fields — the device integrator does not mirror history yet.