Partition Domains
The Partition Domains node () provides an operation that partitions selected domains at specified locations. You can specify the curves or surfaces for the partitioning in various ways (see the Partition with list information under Partition Domains below). Partitioning domains can be useful in cases where a structured mesh would be a better choice than an unstructured mesh but the domains are not suitable for a mapped or swept mesh. A Partition Domains node can occur at any position in the geometry sequence; it works with output geometries before the Form Union/Assembly node, assembly geometries, and virtual geometries. The output of a Partition Domains node’s partitioning operation includes the same number of geometry objects as the input to the partitioning. To add it to a 2D or 3D geometry, in the Geometry toolbar, from the Boolean and Partitions menu (), select Partition Domains. You can also right-click the Geometry node to add this from the Boolean and Partitions submenu. Then enter the properties of the partitioning operation using the following sections:
Partition Domains
In the Domains to partition list, add the domains that you want to partition.
From the Partition with list in 2D, choose one of the following methods for defining the curves for partitioning the domains:
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Choose Line segments between vertices (the default) to define line segments using vertices (points) in the geometry, which you add to the Vertices defining line segments list.
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Choose Lines through vertices to define partitioning lines that pass through the vertices in the Vertices defining lines list. The lines through the vertices extend to the perimeters of the selected domains.
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Choose Edges to select edges in the geometry as the partitioning curves. Add the edges to use for partitioning to the Edges list.
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Choose Extended edges to use the lines and circles defined by straight and circular edges, respectively, as partitioning curves. Add the edges to use for partitioning to the Straight or circular edges list.
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Choose Objects to use geometry objects that you add to the Objects list for partitioning the domains. The objects used for partitioning remain for further geometry operations.
Using the Vertices defining line segments or Vertices defining lines list, it is possible to select any number of vertices (greater than 1). The operation automatically groups the selected vertices into pairs according to minimal distances and defines one partitioning line segment or line per pair.
From the Partition with list in 3D, choose one of the following methods for defining the surfaces for partitioning the domains:
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Choose Work plane (the default) to partition the domain using a work plane that you choose from the Work plane list. Click the Go to Source button () to move to the Work Plane node for the selected work plane.
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Choose Faces to select faces in the geometry as the partitioning faces. Add the faces to use for partitioning to the Faces list.
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Choose Extended faces to use the surfaces defined by planar, cylindrical, and spherical faces as partitioning surfaces. Add the faces to use for partitioning to the Planar, cylindrical, or spherical faces list.
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Choose Objects to use geometry objects that you add to the Objects list for partitioning the domains. The objects used for partitioning remain for further geometry operations. When Objects is selected, you can clear the Keep objects check box (selected by default) to not keep the objects use for the partitioning in the resulting geometry.
The Objects option in the Partition with list is not available if the Partition Domains node appears after the Form Union/Assembly node.
You can change the settings for the Repair tolerance list if you experience problems with the partition operation. Geometric entities that have a distance less than the repair tolerance are merged.
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The default value in the Repair tolerance list is Automatic, which for 3D objects represented using the CAD kernel determines the repair tolerance internally. For 3D objects represented using the COMSOL kernel, and for 2D and 1D objects, Automatic means a relative repair tolerance of 10−6.
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Choose Relative to enter a value for the Relative repair tolerance field (the default is determined by the main Geometry node’s setting). This value is relative to the largest absolute value of the coordinates of all input objects.
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Choose Absolute to enter a value for the Absolute repair tolerance field (the default is determined by the main Geometry node’s setting; SI unit: m). This value uses the same unit as the geometry sequence’s length unit.
When you build this feature, the relative and absolute repair tolerances are set to the values that are used (with a precision of two digits), which can be useful when you have set Repair tolerance to Automatic.
Selections of Resulting Entities
Select the Resulting objects selections check box to create predefined selections for all or some of domains, boundaries, edges, and points that the resulting objects consist of. Select All levels, Domain selection (the default), Boundary selection, Edge selection (3D only), Point selection, of Off from the Show in physics (Show in instances if in a geometry part, Show in 3D if in a work plane’s plane geometry) list. These selections are available in all applicable selection lists under the physics, mesh, materials, and results branches but do not appear as separate selection nodes in the model tree. From the Color list, choose a color for highlighting the resulting objects selection. See Selection Colors.
Cumulative Selection
If you want to make the selections contribute to a cumulative selection, select a cumulative selection from the Contribute to list, or click the New button to create a new cumulative selection (see Cumulative Selections).