TrailRenderer

Leaves a continuous ribbon behind a moving entity.

entity.find("spark").component.add("TrailRenderer", {
    lifetime  = 0.8,
    widthHead = 0.3,
    colorHead = { 1, 0.9, 0.4 },
    colorTail = { 1, 0.2, 0.0 },
})

field	meaning
lifetime	seconds a recorded point survives
minDistance	metres travelled before another point is recorded
maxPoints	bound on how many points the ribbon threads through
widthHead / widthTail	ribbon width at the subject and at the far end
alphaHead / alphaTail	opacity at each end
colorHead / colorTail	RGB at each end; an empty tail holds the head's
orientation	"camera" or "fixed"
up	the axis a "fixed" ribbon opens about
material	the material the ribbon draws with

method
:clear()	drop every recorded point; the ribbon starts again
:pointCount()	how many points the ribbon threads through
:getPath()	the underlying path, for inspection or a custom rebuild
:getRenderEntity()	the entity the ribbon mesh draws from

A subject standing still records nothing, so its trail ages out and disappears rather than pooling at its feet.

Removing the component takes the ribbon and its render entity with it.