Partition Objects
The Partition Objects node () provides a way to partition geometry objects as a Boolean operation. Partitioning geometry objects can be useful to create separate domains or to introduce an interior boundary, for example. Using the Partition Objects node, you can partition a target object using a set of tool objects (geometry objects that are only used to partition — or tool — other geometry objects) or using an (infinite) plane defined by a Work Plane node (you do not need to draw anything in the work plane). The output of a Partition Objects node’s partitioning operation includes the same number of objects as the input to the partitioning. To add it to a model, on the Geometry toolbar Boolean and Partitions () menu, select Partition Objects. You can also right-click the Geometry or a Work Plane>Plane Geometry node to add this from the Boolean and Partitions submenu. Then enter the properties of the partitioning operation using the following sections:
Partition
In the Objects to partition list, add the geometry objects that you want to apply a partition operation on. Click the Active button to toggle between turning ON and OFF the Objects to partition selections.
From the Partition with list, select Objects (the default) to partition using the geometry objects that you add to the Tool objects list below, or select Work plane to partition using any of the added work planes.
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If you select Objects, add the geometry objects that you want to use as tool object to the Tool objects list. Click the Active button to toggle between turning ON and OFF the Tool objects selections. Those geometry objects are only used to partition the geometry objects in the Objects to partition list and are not included in the finalized geometry used for defining materials and physics nodes.
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If you select Work plane, select from the available work planes in the Work plane list. Click the Go to Source button () to move to the Work Plane node for the selected work plane.
Select the Keep input objects check box to use the selected geometry objects to for further geometry operations.
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
If you want to make the resulting entities contribute to a cumulative selection, select a cumulative selection from the Contribute to list (the default, None, gives no contribution), or click the New button to create a new cumulative selection (see Cumulative Selections).
Select the Resulting objects selection check box to create predefined selections (for all levels — objects, domains, boundaries, edges, and points — that are applicable) in subsequent nodes in the geometry sequence. To also make all or one of the types of resulting entities (domains, boundaries, edges, and points) that the resulting objects consist of available as selections in all applicable selection lists (in physics and materials settings, for example), choose an option 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: All levels, Domain selection, Boundary selection, Edge selection, or Point selection. The default is Domain selection, which is suitable for use with materials and physics defined in domains. For use with a boundary condition, for example, choose Boundary selection. These selections do not appear as separate selection nodes in the model tree. Select Off to not make any selection available outside of the geometry sequence.