The operation Remove Details automatically finds and removes small details from the finalized geometry, that is the geometry after the Form Union or Form Assembly node has been built (see Figure 7-41). Small details include vertices with continuous tangent, short edges, small and narrow (sliver) faces, narrow face regions, and thin domains, which may all increase the number of mesh elements significantly. This, in turn, will lead to higher memory consumption. Small details may also influence the quality of the mesh elements, which may affect the possibility to reach a converged solution. Use Remove Details to be in control of where finer mesh is created by removing small details not needed for the simulations. Then, set finer mesh size settings only in regions of importance for the accuracy of the solution.

The Remove Details operation acts on the finalized object and can therefore detect and remove small details created when misaligned objects are united, for example, unintended overlap domains created by slightly overlapping objects. Details are removed by automatically generating a sequence of virtual operations, which are organized in passes with increasing tolerances to remove larger and larger details with each pass. The sequence always ends with a cleanup of edges and vertices.

A geometry may contain details of various sizes which may require different tolerances to remove. Also, some details, even though small, may be important for the simulation results. In these cases, add several Remove Details operations, active on the entire geometry or a selection of entities, and each with its own unique settings. Add manual virtual operations in addition to one or several Remove Details operations, as well as edit the sequence of operations automatically generated by Remove Details. For details about available virtual operations, see links below the Information section.

To add a Remove Details node to a geometry sequence, from the Virtual Operations menu in the context menu when right-clicking a 3D Geometry node or directly from the Geometry ribbon toolbar, choose Remove Details (). The Settings window contains the following sections:

The default in the Mode of operation list is Automatic. Typically, use the automatic mode first. The Remove Details operation generates and builds a local sequence of virtual operations. You can then switch to Manual if needed to inspect the added virtual operations, fine-tune, and add more such operations. When you have built the Remove Details node and the Mode of operation list is set to Manual, the created virtual operations are available as subnodes to the Remove Details node. Alternatively, right-click the Remove Details node and choose Edit Generated Sequence (). You can also then right-click the Remove Details node to add more virtual operations. If you want to restore the generated sequence of virtual operations, choose Reset to the Generated Sequence () from the Remove Details node’s context menu.

The following sections are only available when the Mode of operation list is set to Automatic.

The default is to remove small details from the entire geometry. From the Entities list, choose Selection instead of Entire geometry to make a selection of entities for which you want to remove small details.

If you choose Selection, the Geometric entity level list appears with the options Domain (the default), Boundary, and Edge. If the geometry sequence includes user-defined selections, you can choose one of them from the Selection list; otherwise, or if you choose Manual from the Selection list, select entities from the Graphics window or by pasting selections into the list of selected entities.

All check boxes are selected by default. When the remove details operation has finished, information about the number of removed details appears in the table under Information.

From the Detail size list, choose Automatic (the default), Relative, or Absolute. If you choose Relative the Maximum relative size field appears. The default relative tolerance used is 0.001 which is relative to the length of the longest edge of the selection’s bounding box. If you select Absolute, the Maximum absolute size field appears. The default tolerance used is 0.001 times the longest edge of the geometry’s bounding box. When you build this feature, the Maximum relative size and the Maximum absolute size are set to the values that are used, which can be useful when you have set Detail size to Automatic.

The values in the Continuous tangent tolerance field (default value: 5 degrees) specifies the maximum allowed angular tangent deviation across a vertex or edge to be ignored.

This section contains information about the removed details: In the Type of removal column, the types of details that have been removed are listed. In the Removed entities column, the number of entities for each type of remove operation is listed.

Click Build Selected () (or press F7) to build the geometry up to and including this node, click Build Preceding () (or press F6) to build the geometry up to the node preceding this node, or click Build All () (or press F8) to build all nodes in the geometry sequence.