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KB 001617 | Selecting Nodes Along Line via COM Interface

Topic:
Selecting Nodes Along Line via COM Interface

Annotation:
If you read out the results of a surface by means of the COM interface, you get a one-dimensional field with all results at the FE nodes or grid points. To get the results on the edge of a surface or along a line within the surfaces, you have to filter out the results in the area of the line. The following article describes a function for this step.

Description:
Theoretical Background for Distance Calculation

To find the FE nodes that are close to or on the line, it is necessary to calculate the distance of the node to the line. The line with the start and end points (N-0 and N-1), and the point P of which the distance to the line is to be determined, are given. A common way to calculate this distance is to span a plane that runs through point P and is perpendicular to the straight line. For this purpose, a suitable linear equation has to be set up first. In this case, we recommend using the parameter form, which contains a direction vector v. You can use it to set up the plane equation.

The support vector P is the result point P-res to be analyzed. The normal vector is the direction vector of the straight line because the plane is orthogonal to the straight line. Before the distance can be calculated, it is necessary to determine the factor s of the line where the plane intersects the line. For this purpose, the location vector X in the plane equation is replaced by the straight line equation.
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