This attribute controls whether points on the boundary of a
Region are
considered to be inside or outside the region. If the attribute value is non-zero (the
default), points on the boundary are considered to be inside the region (that is, the
Region is
"
closed
"
). However, if the attribute value is zero, points on the bounary
are considered to be outside the region.
Region
All Regions have this attribute.
The value of the Closed
attribute is ignored by PointList regions. If the PointList region has not been
negated, then it is always assumed to be closed. If the PointList region has been
negated, then it is always assumed to be open. This is required since points have
zero volume and therefore consist entirely of boundary.
The
default Closed value for a CmpRegion is the Closed value of its first component
Region.
The default Closed value for an Stc is the Closed value of its
encapsulated Region.
The Moc class ignored this attribute, and the
behaviour for boundary points is undefined (i.e. they may be inside or outside the
Region, depending on the position being tested and the nature of the Moc).