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 toolbar, click (

) or right-click a 3D node and select . Then enter the properties defining the location of the work plane in the following sections of its window.

	Using Work Planes

The layout of the section depends on the selection in the list, where you select how to define the work plane. Choose one of the following types:

In the 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 list:

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(the default) to define the distance from the coordinate plane in the third axis’ direction using the , , or field (default value: 0; that is, no offset).

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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 button to toggle between turning ON and OFF the selections.

Select a planar face in the window that is parallel to the work plane you want to create with the list set to , or choose any applicable geometry object or selection. The list below then shows the selected face. Click the button to toggle between turning ON and OFF the selections. Specify an offset using one of the following settings in the list:

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(the default) to define the distance in the 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 list. The default value: 0; that is, no offset.

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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 button to toggle between turning ON and OFF the selections.

To reverse the direction of the z-axis of the work plane’s coordinate system, select the check box. This also swaps the coordinate axes in the work plane to preserve the positive orientation of the local coordinate system.

Select a planar edge (that is not straight) in the window that is parallel to the work plane you want to create with the list set to , or choose any applicable geometry object or selection. The list below then shows the selected edge. Click the button to toggle between turning ON and OFF the selections.

Specify an offset using one of the following settings in the list:

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(the default) to define the distance in the 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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Activate the list by first selecting its button and then select a straight edge with the list set to , or choose any applicable geometry object or selection. The list below then shows the selected edge. Similarly, activate the list by first clicking its button and then select an adjacent face in the window or from the list. Also, specify a value in the 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 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.

Activate the list by clicking its button. Then select a circular edge in the window. This results in a work plane perpendicular to the given circular edge. Use the list to choose a vertex that the plane should go through:

You can then rotate the work plane around the normal direction of the circle’s plane by specifying an (in degrees; default value: 0 degrees). You can also reverse the work plane’s normal direction using the 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 node to get a 2D axisymmetric geometry corresponding to a rotationally symmetric 3D geometry.

Use this work plane type to orient an object so that one of its planar faces gets a prescribed normal vector.

Under , in the , , and fields (SI unit: m), enter the components of the normal vector.

Under , from the list, choose (the default) or . For , enter the coordinates for a point on the plane in the , , and fields (SI unit: m). For , select a vertex in the geometry, or if available, use a user-defined vertex selection.

In each of the lists , , and , select a vertex by first clicking the corresponding button and then selecting a vertex in the window. This creates a work plane parallel to a plane through the three vertices.

Specify an offset in the 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 check box.

This choice creates a work plane through the three points with the given coordinates. The origin of the local coordinate system coincides with . The x-axis of the local coordinate system is in the direction of the vector from to . The positive direction of the y-axis is determined by the condition that the vector from to has a positive y-component.

Use the work plane type to create a work plane using a transformation of another work plane. From the list, select (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 list, select an available work plane (for example, ) from the selected geometry sequence or select (the default).

Under , enter the desired displacements in the work plane’s x, y, and z directions in the , , and 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 , from the list, choose (the default, , or as the way to specify the rotation.

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For , select an : , , (the default), , or . For any choice, enter an (SI unit: degrees; default 0) to specify the rotation (see 2D Settings above). If is selected, enter Cartesian coordinates values for , , and (default values 0, 0, and 1, respectively, corresponding to the global z-axis) to specify the axis vector. If is selected, specify the axis vector using spherical angles and in degrees (default: 0).

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For , choose a straight edge as the axis of rotation and add it to the list. For , select a straight edge in the Graphics window by first enabling the selection in the list. Using a preselection, you can add it using the button (

). Use the button (

) to remove the selected straight edge and the button (

) to zoom into the selected straight edge.

Enter an (SI unit: degrees; default 0) to specify the rotation angle for the transformation.

In this section you specify the local coordinate system in the work plane for most work plane types.

In the work plane type:

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In the list, choose the location of the origin of the work plane’s coordinate system: (the default) or . In the latter case, also pick a vertex for the origin, which you add to the list under (manually or by choosing an applicable geometry object or selection).

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In the list, choose how to define the local x-axis: (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 to define the local x-axis through a vertex projection. Then choose a vertex for the local x-axis that you add to the list (manually or by choosing an applicable geometry object or selection).

In the plane type:

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In the list, choose the location of the origin of the work plane’s coordinate system: (the default), , or . In the last case, choose a vertex for defining the origin that you add to the list.

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In the list, choose how to define the local x-axis: (the default) or , which are the local parameter directions of the face (represented by the variables s1 and s2, respectively). Alternatively, choose to define the local x-axis through a vertex projection. Then choose a vertex for the local x-axis that you add to the list.

In the plane type:

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In the list, choose the location of the origin of the work plane’s coordinate system: The (the default) or of the edge, or . In the last case, choose a vertex for defining the origin that you add to the list.

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In the list, choose how to define the local x-axis: (the default), which means that the local x-axis follows the direction of the edge’s tangent. Alternatively, choose to define the local x-axis through a vertex projection. Then choose a vertex for the local x-axis that you add to the list.

In the , , , , , , and work plane types:

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Enter displacements within the plane in the and 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 field if you want to rotate the local coordinate system. The default is 0 degrees; that is, no rotation. In the 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 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.

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 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 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 list is , 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, means a relative repair tolerance of 10−6.

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Choose to enter a value for the field (the default is determined by the main node’s setting). This value is relative to the largest absolute value of the coordinates of all input objects.

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Choose to enter a value for the field (the default is determined by the main 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 to .

	This section is only available for work planes in geometry parts.

Select the check box (selected by default) to make the work plane available in the nodes’ settings.

Select the 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 ( if in a geometry part) list: , (in geometry parts only), , , or . The default is . These selections do not appear as separate selection nodes in the model tree. Select to not make any selection available outside of the geometry sequence. From the list, choose a color for highlighting the resulting objects selection. See Selection Colors.

Under , select the ( 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.

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 list (the default, , gives no contribution), or click the button to create a new cumulative selection (see Cumulative Selections).

Select the check box to make the resulting objects available only in the feature’s geometry sequence. For more information, see Construction Geometry.

To go to the planar geometry, click the button (

) in the window’s toolbar, or click the node that appears under the node. To create 2D objects in the work plane, right-click the node and create nodes like in a 2D geometry.

To embed the 2D work plane geometry in the 3D geometry, build the Work Plane feature by either right-clicking the node and choosing or selecting the node and then clicking or .