Cut Line 2D and Cut Line 3D
Use a Cut Line 2D () or Cut Line 3D () dataset to create lines through 2D or 3D geometries to visualize along the line. All plots and results analysis nodes available in 1D are available for cut line datasets as well as 3D plots and results analysis nodes for edges. These datasets are also used to create cross-section line plots. The resolution of cut lines is controlled by the resolution of the underlying mesh and by the resolution setting in the Quality section in plots. If you need full control over the resolution, use a Parameterized Curve dataset (see Parameterized Curve 2D and Parameterized Curve 3D). You can right-click a Cut Line 2D or Cut Line 3D dataset node to add a Selection subnode if desired.
Go to Common Results Node Settings for links to information about the Data section.
Line Data
Use Line entry method to specify the cut line either by Two points or by a Point and direction. If Two points is selected, enter x and y coordinates (2D) or x, y, and z coordinates (3D) in the Point 1 and Point 2 fields ((SI unit: m). If Point and direction is selected, enter x and y coordinates (2D) or x, y, and z coordinates (3D) in the Point (SI unit: m) and Direction fields.
The Bounded by points check box is selected by default to constrain the line between the defined points.
From the Snapping list, choose None for no snapping (the default), Snap to closest boundary to snap the cut lines to the closest boundary in the geometry, or Snap to closest edge (Cut Line 3D only) to snap the cut lines to the closest edge in the geometry. Use this option when evaluating a variable that is available on boundaries but not in domains, for example. Otherwise, leave the snapping off (the default setting, None) to avoid the additional computational cost. However, snapping always happens if the underlying dataset has a shell geometry.
For Cut Line 2D, also select the Additional parallel lines check box to define multiple lines for plotting or evaluation, for example. Then enter Distances from the original line in the field. The Distances field refers to a direction that is normal to the cut line and rotated 90 degrees counterclockwise relative to the cut line’s direction. For example, if the cut line is from (0, 0) to (1, 0), then the distances are along the vector (0, 1) from any point on the cut line.
Advanced
Under Space variable, you can change the name of the space variable for the cut line’s coordinate from its default value (cln1x, for example). The space variable name shows in the Table window when displaying the data. For Cut Line 2D nodes, normal variables are created, and under Normal variables, you can change the default names (cln1nx and cln1ny, for example) in the nx and ny fields. Tangent variables are also created for Cut Line 2D and Cut Line 3D nodes. Under Tangent variables, you can change the default names (cln1tx, cln1ty, and cln1tz, for example, in 3D) in the tx, ny, and tz fields. The normal and tangent vectors defined using these variables have unit length.
For a Cut Line 3D example, see Thin-Film Resistance: Application Library path COMSOL_Multiphysics/Electromagnetics/thin_film_resistance.