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variable: $samevtxthickflag -- samevtx vs. norm
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default: 0

"NormSamp, Clust Controls" parameter.  To adjust,
access pop-up by L-click on "label:" (bold).

This flag affects the operation of both of the
following functions:

  write_label_timecourses_stats
  ("label:" line "T" and "S" buttons)

  paint_surface
  ("val3d:" line "PAINT" button)

If not ticked, search takes place along the local
surface normal (in mm, or as fraction of
thickness).

If ticked, search takes place along the vector to
the same-numbered vertex on the pial surface
instead of the surface normal.  If search is done
as fraction ($normdfracflag ticked), the
thickness is redefined as the distance to the
same-numbered vertex.
