Import Section from CAD File

In CAD import dialog chosen CAD files are listed. Cross sections need to be meshed before they can be imported to the Modeler.

Note: Cross sections from CAD file should:

not contain any constraint lines except closed holes,
contain only closed outer boundaries which can contain only closed holes,
contain only boundaries that do not touch.

Import works in three steps:

Add files to the list. It is impossible to import cross section at this stage yet, because no mesh exist. Preview window shows boundaries of selected CAD model by yellow color.
Select file and generate a mesh. Button Generate mesh becomes enabled after selecting the file in the list and user can mesh the shape. User should see the faces colored by white if meshing succeeds. Later on user can change any parameter and mesh will be automatically recalculated.
Import mesh to the Modeler. Button Import is enabled after meshing and user can import generated cross section to the Modeler. CAD file is removed from the list if import succeeds.

Setting	Description
Add file	Select CAD file(s). The list is populated with new entries.
Rename cross section	New name of cross section can be set. Note: Cross section with same name will be overwritten.
Delete line	Deletes cross section CAD file from the list.
Unit	Unit used in original CAD file.
Tolerance	Two or more points from original CAD file that lie within given tolerance will be merged into single point.
Align x-coordinates	Position of origin Y axis: None, Left, Right or Center. Parameter "at" shifts construction line by given distance.
Align y-coordinates	Position of origin X axis: None, Top, Bottom, Center. Parameter "at" shifts construction line by given distance.
Mesh type	Note: Quad-dominant. It forces to generate mesh containing mostly quads, but few triangles may be generated to keep good mesh quality. Note: Only quads. It forces to generate mesh containing only quads. To accomplish that goal even number of points at each boundary is needed. For that reason every line segment of the boundary gets at least one additional point.
Boundary edge length	It describes how many additional points should appear at boundary. Long boundary edge will be subdivided into smaller edges with given length. Initial boundary edge length is set to 10% of cross section width (cross section width is shown in preview).
Meshing options	Note: Intersect boundary with middle y axis. Mass of gravity is calculated and Y axis with its X coordinate is generated. That axis is intersected with the shape to generate additional points at cross section boundaries. That effect may generate good left-right symmetric mesh. Note: Minimize number of inside points. If user wants to get a mesh consisting mostly of points at the boundary and avoid new points within the boundary, then he should use that flag.
Generate Mesh	Create initial mesh after selecting CAD file in the list. Any further changes of parameters will recreate mesh automatically. Initial meshing is necessary to be fired from the user for one reason: user may want to fill the list with hundreds of CAD files, but searches only for few shapes (no need for time consuming initial meshing of hundreds of shapes).
Close	Returns to the main window without any action.