Iterates over all intersection groups and updates their stop-line colours
to match the current traffic-signal phase reported by the intersection
controller.
Colour values are cached on group.userData._stopLineLastColours so that
the underlying ThickLineHandle is only updated when the phase
actually changes, avoiding unnecessary GPU work.
Iterates over all intersection groups and updates their stop-line colours to match the current traffic-signal phase reported by the intersection controller.
Colour values are cached on
group.userData._stopLineLastColoursso that the underlying ThickLineHandle is only updated when the phase actually changes, avoiding unnecessary GPU work.