Work Plane
To create a work plane for defining 2D objects in 3D (for example, for extruding a 2D object into a 3D object) or for defining the placement of the resulting objects of a Part Instance, in the Geometry toolbar, click Work Plane () or right-click a 3D Geometry node and select Work Plane. Then enter the properties defining the location of the work plane in the following sections of its Settings window.
Using Work Planes
Plane Definition
Plane Type
The layout of the Work Plane section depends on the selection in the Plane type list, where you select how to define the work plane. Choose one of the following types:
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Quick (the default)
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Face parallel
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Edge parallel
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Edge angle
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Circle perpendicular
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Normal vector
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Vertices
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Coordinates
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Transformed
Quick
In the Plane list, select one of the global coordinate planes xy, yz, zx, yx, zy, or xz, denoting the first and second axes of the work plane’s local coordinate system. Specify an offset using one of the following settings in the Offset type list:
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Distance (the default) to define the distance from the coordinate plane in the third axis’ direction using the z-coordinate, x-coordinate, or y-coordinate field (default value: 0; that is, no offset).
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Through vertex to define the position of the work plane in the third direction by selecting a vertex. The work plane’s position then contains that vertex. Click the Active button to toggle between turning ON and OFF the Offset vertex selections.
Face parallel
Select a planar face in the Graphics window that is parallel to the work plane you want to create with the Planar face list set to Manual, or choose any applicable geometry object or selection. The list below then shows the selected face. Click the Active button to toggle between turning ON and OFF the Planar face selections. Specify an offset using one of the following settings in the Offset type list:
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Distance (the default) to define the distance in the Offset in normal direction field. You then offset the work plane along the normal of the planar face. By default, the work plane’s normal is the outward normal of the face in the Planar face list. The default value: 0; that is, no offset.
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Through vertex to define the position of the work plane in the third direction by selecting a vertex. The work plane’s position then includes the position of that vertex. Click the Active button to toggle between turning ON and OFF the Offset vertex selections.
To reverse the direction of the z-axis of the work plane’s coordinate system, select the Reverse normal direction check box. This also swaps the coordinate axes in the work plane to preserve the positive orientation of the local coordinate system.
Edge parallel
Select a planar edge (that is not straight) in the Graphics window that is parallel to the work plane you want to create with the Planar curved edge list set to Manual, or choose any applicable geometry object or selection. The list below then shows the selected edge. Click the Active button to toggle between turning ON and OFF the Planar curved edge selections.
Specify an offset using one of the following settings in the Offset type list:
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Distance (the default) to define the distance in the Offset in normal direction field. You then offset the work plane along the normal of the plane containing the edge. The default value: 0; that is, no offset.
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Through vertex to define the position of the work plane in the third direction by selecting a vertex. The work plane’s position then includes the position of that vertex. Click the Active button to toggle between turning ON and OFF the Offset vertex selections.
To reverse the direction of the z-axis of the work plane’s coordinate system, select the Reverse normal direction check box. This also swaps the coordinate axes in the work plane to preserve the positive orientation of the local coordinate system.
Edge angle
Activate the Straight edge list by first selecting its Active button and then select a straight edge with the Straight edge list set to Manual, or choose any applicable geometry object or selection. The list below then shows the selected edge. Similarly, activate the Face adjacent to edge list by first clicking its Active button and then select an adjacent face in the Graphics window or from the list. Also, specify a value in the Angle between face and work plane field (in degrees; the default value is 0). This results in a work plane through the given edge that makes the specified angle with the adjacent face.
By default, the origin of the local coordinate system coincides with the edge’s end vertex, and the direction of the local x-axis is opposite to the direction of the edge. If you select the Reverse normal direction check box, the origin instead is at the start vertex, and the direction of the local x-axis coincides with the direction of the edge.
Circle perpendicular
Activate the Circular edge list by clicking its Active button. Then select a circular edge in the Graphics window. This results in a work plane perpendicular to the given circular edge. Use the Point on plane list to choose a vertex that the plane should go through:
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The edge’s Start vertex (the default)
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The edge’s End vertex.
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Some Other vertex, which you can choose from the Vertex list that opens.
You can then rotate the work plane around the normal direction of the circle’s plane by specifying an Angle offset (in degrees; default value: 0 degrees). You can also reverse the work plane’s normal direction using the Reverse normal direction check box.
The origin of the local coordinate system is at the circle’s center. The local x-axis goes through the circle. Thus, if the geometry is rotationally symmetric, the symmetry axis coincides with the local y-axis. You can use this type of work plane together with a Cross Section node to get a 2D axisymmetric geometry corresponding to a rotationally symmetric 3D geometry.
Normal vector
Use this work plane type to orient an object so that one of its planar faces gets a prescribed normal vector.
Under Normal vector, in the x, y, and z fields (SI unit: m), enter the components of the normal vector.
Under Point on plane, from the Specify list, choose Coordinates (the default) or Vertex. For Coordinates, enter the coordinates for a point on the plane in the x, y, and z fields (SI unit: m). For Vertex, select a vertex in the geometry, or if available, use a user-defined vertex selection.
Vertices
In each of the lists First vertex, Second vertex, and Third vertex, select a vertex by first clicking the corresponding Active button and then selecting a vertex in the Graphics window. This creates a work plane parallel to a plane through the three vertices.
Specify an offset in the Offset in normal direction field (default value: 0; that is, no offset). The origin of the local coordinate system is located above the first vertex, and the vector to the second vertex becomes the local x-axis. Reverse the directions of the local z-axis and y-axis by selecting the Reverse normal direction check box.
Coordinates
This choice creates a work plane through the three points with the given coordinates. The origin of the local coordinate system coincides with Point 1. The x-axis of the local coordinate system is in the direction of the vector from Point 1 to Point 2. The positive direction of the y-axis is determined by the condition that the vector from Point 1 to Point 3 has a positive y-component.
Transformed
Use the work plane type to create a work plane using a transformation of another work plane. From the Take work plane from list, select This sequence (the default) to use a work plane earlier in the same geometry sequence, or choose a geometry part that this geometry sequence calls earlier in the sequence. From the Work plane to transform list, select an available work plane (for example, Work Plane 1 {wp1}) from the selected geometry sequence or select xy-plane (the default).
Under Displacement, enter the desired displacements in the work plane’s x, y, and z directions in the xw, yw, and zw fields, respectively. The defaults are 0 (that is, no displacement). The displacements are specified in the local coordinate system of the input work plane before the rotation (below) is applied.
Under Rotation, from the Specify list, choose Axis of rotation (the default, Euler angles (Z-X-Z), or Edge as the way to specify the rotation.
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For Axis of rotation, select an Axis type: xw-axis, yw-axis, zw-axis (the default), Cartesian, or Spherical. For any choice, enter an Angle (SI unit: degrees; default 0) to specify the rotation (see 2D Settings above). If Cartesian is selected, enter Cartesian coordinates values for x, y, and z (default values 0, 0, and 1, respectively, corresponding to the global z-axis) to specify the axis vector. If Spherical is selected, specify the axis vector using spherical angles theta and phi in degrees (default: 0).
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For Euler angles (Z-X-Z), enter values for the intrinsic Z-X-Z Euler angles α, β, and γ in the corresponding text fields (in degrees; the default values are 0).
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For Edge, choose a straight edge as the axis of rotation and add it to the Straight edge list. For Edge, select a straight edge in the Graphics window by first enabling the selection in the Straight edge list. Using a preselection, you can add it using the Add to Selection button (). Use the Clear Selection button () to remove the selected straight edge and the Zoom to Selection button () to zoom into the selected straight edge.
Enter an Rotation angle (SI unit: degrees; default 0) to specify the rotation angle for the transformation.
Local Coordinate System
In this section you specify the local coordinate system in the work plane for most work plane types.
In the Quick work plane type:
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In the Origin list, choose the location of the origin of the work plane’s coordinate system: Global (the default) or Vertex projection. In the latter case, also pick a vertex for the origin, which you add to the list under Vertex for origin (manually or by choosing an applicable geometry object or selection).
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In the Local x-axis list, choose how to define the local x-axis: Natural (the default), which means that the local x-axis corresponds to the first direction in the plane; for example, the y direction for a yz-plane. Alternatively, choose Through vertex projection to define the local x-axis through a vertex projection. Then choose a vertex for the local x-axis that you add to the Vertex for axis list (manually or by choosing an applicable geometry object or selection).
In the Face parallel plane type:
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In the Origin list, choose the location of the origin of the work plane’s coordinate system: Center of face (the default), Bounding box corner, or Vertex projection. In the last case, choose a vertex for defining the origin that you add to the Vertex for origin list.
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In the Local x-axis list, choose how to define the local x-axis: First parameter direction (the default) or Second parameter direction, which are the local parameter directions of the face (represented by the variables s1 and s2, respectively). Alternatively, choose Through vertex projection to define the local x-axis through a vertex projection. Then choose a vertex for the local x-axis that you add to the Vertex for axis list.
In the Edge parallel plane type:
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In the Origin list, choose the location of the origin of the work plane’s coordinate system: The Start vertex (the default) or End vertex of the edge, or Vertex projection. In the last case, choose a vertex for defining the origin that you add to the Vertex for origin list.
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In the Local x-axis list, choose how to define the local x-axis: Tangent direction (the default), which means that the local x-axis follows the direction of the edge’s tangent. Alternatively, choose Through vertex projection to define the local x-axis through a vertex projection. Then choose a vertex for the local x-axis that you add to the Vertex for axis list.
In the Quick, Face parallel, Edge parallel, Edge angle, Circle perpendicular, Normal vector, and Vertices work plane types:
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Enter displacements within the plane in the xw-displacement and yw-displacement fields if you want to move the origin of the local coordinate system. The displacements are specified in the original local coordinate system, before the rotation angle (below) is applied. The defaults are 0.
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Enter a rotation angle in the Rotation field if you want to rotate the local coordinate system. The default is 0 degrees; that is, no rotation. In the Normal vector case, the default yw-axis goes in the direction (−ny, nx,0), where (nx, ny, nz) is the given normal vector, except if the plane is parallel with the xy-plane, in which case the direction is (0, 1, 0).
The Show in graphics check box is selected by default to display the local coordinate system. Clear this check box to remove the display of the local coordinate system.
Unite Objects
By default, the COMSOL Multiphysics software unites all objects in the 2D work plane, which can make it easier to, for example, extrude the 2D geometry into a 3D geometry object.
Clear the Unite objects check box if you do not want to unite the separate 2D geometry objects in the work plane. If the check box is selected, you can change the settings for the Repair tolerance list if you experience problems with the unite operation. Objects 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.
Part Instances
This section is only available for work planes in geometry parts.
Select the Show work plane in instances check box (selected by default) to make the work plane available in the Part Instance nodes’ settings.
Selections of Resulting Entities
Select the Resulting objects selection check box to create predefined selections (for all levels — objects, domains, boundaries, 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) list: All levels, Object selection (in geometry parts only), Boundary selection, Edge selection, or Point selection. The default is 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. From the Color list, choose a color for highlighting the resulting objects selection. See Selection Colors.
Under Selections from plane geometry, select the Show in physics (Show in instances if in a geometry part) check box to show selections from the work plane’s plane geometry in the physics or in part instances. For example, a selection in the plane geometry can be used as the boundaries for a boundary condition in the 3D physics.
Cumulative Selection
If you want to make the resulting entities that the 2D geometric objects in the work plane consist of 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).
Assigned Attributes
Select the Construction geometry check box to make the resulting objects available only in the feature’s geometry sequence. For more information, see Construction Geometry.
Drawing in the Work Plane
To go to the planar geometry, click the Go to Plane Geometry button () in the Settings window’s toolbar, or click the Plane Geometry node that appears under the Work Plane node. To create 2D objects in the work plane, right-click the Plane Geometry node and create nodes like in a 2D geometry.
Embedding the Work Plane in the 3D Geometry
To embed the 2D work plane geometry in the 3D geometry, build the Work Plane feature by either right-clicking the Work Plane node and choosing Build Selected or selecting the Work Plane node and then clicking Build Selected or Build All Objects.