Import mesh from a file, from another meshing sequence, from a geometry sequence, or from a Filter (Dataset) or Partition dataset. You can import a mesh from a COMSOL Multiphysics file and Sectionwise file. In 3D, you can also import meshes from 3MF, NASTRAN, PLY, STL, and VRML files. In 2D, you can also import meshes from NASTRAN (the third coordinate must then be the same for all mesh points) and COMSOL’s native formats.

Use a Transform attribute to position, rotate, or scale an imported mesh.

Use model.component(<ctag>).mesh(<tag>).create(<ftag>,"Import") to import a mesh into a meshing sequence that defines its own geometrical model. See the section Geometric Model for more information. If the sequence already contains a mesh, the imported mesh is added to the existing mesh.

Use model.component(<ctag>).mesh(<tag>).feature(<ftag>).importData() to import the file again.

The available properties are listed in the tables below. Table 4-2 lists properties common for many of the import sources:

The following tables list additional properties depending on which source property is used.

The properties stltolabs, stltolrel, stltoltype, and selectionstl are only used for import of STL files. If selectionstl is active, the following tags are assigned to the created selections:

The tags of the imported selections can also be obtained by calling the outputSelection() function on the mesh import feature.

The tag of the model selection becomes <meshing sequence tag>_<import node tag>_<selection tag>, such as mesh1_imp1_sel.

The property buildsource is only used when source is sequence. If buildsource is active, the source sequence is always built and the current version of the source mesh is imported. This is required when running a parametric sweep that influences the source meshing sequence. If the property is deactivated, run the method importData() to manually build and reimport the source mesh sequence.

The properties linearelem, materialsplit, and data are only used for import of NASTRAN files. The properties selcreation and allowshellpartition are only used when materialsplit is on.

linearelem specifies if the elements in the NASTRAN or COMSOL Multiphysics file are imported as linear elements. If the value is on all imported elements are linear. Otherwise, the order of the imported elements is determined from the order of the elements in the file. The default value is off.

materialsplit determines if material data in the file is used (if available) to determine the domain partitioning of the domain elements. If the value is off all domain elements in the imported mesh belongs to the same domain if possible. The default value is off.

If you set facepartition to minimal, the operation keeps the original partition from the file (if any), adding minimal partitioning in order to satisfy topological requirements.

If you set facepartition to manual, you can use the following properties. If you set any of these properties without setting facepartition to manual, the operation automatically switches facepartition to manual.

The following properties are available in 3D when facepartition is set to detectfaces:

The table below specifies the properties for selections imported when source is file, stl, or dataset.

If no selection of a certain dimension is imported, the length of the corresponding array is 0.

The values of the selection properties can be set using individual names accompanied by an index between 0 and length-1

where <nname> is the new name for the selection on place <index> in the property array. An alternative is to set the entire string array at once

where <narray> is a new array of strings of correct length.

The NASTRAN bulk data format uses reduced second-order elements; that is, the center node on quadrilateral mesh faces (quadNode) and the center node of hexahedral elements (hexNode) are missing. Importing a NASTRAN mesh with second-order elements, COMSOL Multiphysics interpolates the coordinates of these missing node points from the surrounding node points using the following formulas: quadNode = 0.5*quadEdgeNodes - 0.25*quadCornerNodes, where quadEdgeNodes is the sum of the coordinates of the surrounding 4 edge nodes and quadCornerNodes is the sum of the coordinates of the surrounding 4 corner nodes, and hexNode = 0.25*hexEdgeNodes-0.25*hexCornerNodes, where hexEdgeNodes is the sum of the coordinates of the surrounding 12 edge nodes and hexCornerNodes is the sum of the coordinates of the surrounding 8 corner nodes.

The source property value stlvrml has been replaced by separate stl and vrml values in version 5.5. The value stlvrml is also accepted for backward compatibility. If a filename is given and it ends with .vrml, source is then set to vrml. Otherwise, source is set to stl.

The elemsplit property from earlier versions is no longer available from version 5.3.

For 3D meshing sequences, the setting manual of the property facepartition in the mesh Import feature, as well as all the properties associated with this setting, are deprecated as of COMSOL 5.1 and may be removed in a future version. In COMSOL 5.1, these properties are still available with unchanged behavior for backward compatibility.

Transform, Ball, Box, CreateVertices, DeleteEntities, DetectFaces, JoinEntities, LogicalExpression, Filter (Dataset), Partition