Optional ReadonlycolorTrail Color.
"particle" uses each particle's own (front) color.
Optional ReadonlylengthTrail Length. How many recent positions (one per frame) the trail runs through. Clamped to 2–32.
Optional ReadonlyopacityHead Opacity. Opacity right behind the particle, fading to transparent at the tail. It is multiplied by the particle's own fade, so trails vanish with their particle. Clamped to 0–1.
Optional ReadonlywidthHead Width. Line width right behind the particle; the trail tapers to nothing at its tail.
Motion Trail Settings. Draws a short streak behind each particle through its last positions, thinning and fading toward the tail — sparks, comets, fireworks.
Example
Remarks
Each trail segment is one stroke:
length10 costs about 10 extra draw calls per particle. Keeplengthmodest for large bursts.