Committed visible-element count of a child's leaf mesh, or null when
untracked. Reads the per-type commit stamps (visiblePointCount /
visibleSegmentCount / visibleSplatCount / visibleTriangleCount —
written by the commit-*-geometry helpers). Non-leaf children (nested groups) and
not-yet-committed leaves carry no stamp and return null — callers must
only act on a KNOWN-empty level (0), never on null.
Committed visible-element count of a child's leaf mesh, or
nullwhen untracked. Reads the per-type commit stamps (visiblePointCount/visibleSegmentCount/visibleSplatCount/visibleTriangleCount— written by the commit-*-geometry helpers). Non-leaf children (nested groups) and not-yet-committed leaves carry no stamp and returnnull— callers must only act on a KNOWN-empty level (0), never onnull.