When
a X-Topology surface is generated the last face (patch) to be identifed
will generally mark the boundary. For this to happen the references topology
curves must form an easily identifyable surface. However, sometime the definition
may be closed and the form produced by the X-Topolology surface will be
more solid with every face filled in. It is possible to inform the surface
generation process that it should not patch a face by marking the boundary
curves with the 'Force Curve to Surface Boundary' The surface modeller will
not create a patch on a face where all the curve edges have been marked
with this attribute. This option is available from X-Topology Curve menu,
, and the multiple selection menu
.