Creating a Closed Surface

You want to create a closed surface, i.e. a surface with no boundary.
The Boundary Definition action enables us to check whether there is a boundary or not,
i.e. whether the surface is closed or not.

  1. Click Boundary in the Operations toolbar and select Join.1.

  2. Click OK. A message appears about the Multi-Result Management. Select keep all the sub-elements.
    Boundary.1     is created under Geometrical Set.2.

  3. This shows that there is a boundary, made of several sub-elements, which means the surface is not closed.
    You are going to perform a local join on this boundary:
    • as you enter the boundary to process, the action searches the gaps that may exist,
      and indicates the size of the largest gap found in the field near Automatic Merging.
    • This gap is larger than the Merging Distance used in the Global Join.
      Performing a Global Join with the value of this gap would merge elements that you do not want
      to merge because this would deform the model.
    • Performing a Local Join with this value on the boundary only avoids deforming the model and
      ensures the model is closed.

  4. Click Local Join in the Repair Topology toolbar and select Boundary.1.

  5. The size of the largest gap found is 0.1 mm.
    This determines the Join Merging Distance: enter 0.1 mm in the Join Merging Distance box .
    Click OK. LocalJoin.1 is created under Geometrical Set.2.

  6. Click Boundary and select the surface again. A message appears.

    The surface has no boundary: it is closed.