Common Virtual Topology Operations

This section describes common virtual topology operations.

Importing Legacy Models

Upon import of a legacy model into release 2024 R2, suppressed virtual topology entities will be deleted. This includes any virtual topology entities that were suppressed manually (for example, by right-clicking on the virtual topology entity in the Tree Outline and selecting Suppress from the context menu), but it does not include virtual topology entities that are suppressed because the body containing them is suppressed. If entities are deleted, a warning message will be issued advising you to import the model into an earlier release, unsuppress the affected entities, and save the model for use in release 2024 R2.

Handling of Geometry Changes That Result in Incomplete Virtual Entities

The Virtual Topology object that appears in the Tree Outline represents all definitions of virtual face or virtual edge groups, and all definitions of virtual split edges, virtual split faces, and virtual hard vertices within a model. Individual objects for these virtual entities do not appear in the Tree. If a geometry operation invalidates a virtual entity, refreshing the geometry does not cause the Virtual Topology object in the Tree Outline to become underdefined. For example, if you include a fillet and one neighboring face in the creation of a virtual cell, but later remove the fillet from the CAD model and refresh the geometry, that individual virtual cell will become underdefined (as it only includes the one neighboring face), but it will not be deleted, and there will be no change in the Tree Outline. If in a later operation, the fillet is re-added to the CAD model and refreshed, the virtual cell will be restored. When a virtual entity becomes underdefined due to a geometry operation, a message is issued. You might be able to view partial Virtual Entities by right-clicking on the Show Problematic Geometry message.

Underdefined Virtual Topologies are not displayed in Virtual Topology graphics, nor are they included in Virtual Topology statistics.

Note:  If you suppress a part or all bodies in a multibody part in the DesignModeler application, and refresh the geometry in the Meshing application, any virtual topology that had been defined on those bodies will be removed. The virtual topology will not be removed if only some bodies within a multibody part are suppressed in DesignModeler.

Using Named Selections with Virtual Topology

If you are using Named Selections with virtual topology and you subsequently modify the virtual topology, you must manually update the Named Selections. For example, if you create a Named Selection to define local inflation and then define virtual topology on that Named Selection, you must update the Named Selection before generating the mesh or the inflation will not be defined correctly. This limitation does not always occur if you perform a similar operation using the DesignModeler application. For example, after you perform a merge operation in DesignModeler, the software may be able to relink the Named Selection to the topology automatically when the geometry is refreshed.

Cycling Through Virtual Entities in the Geometry Window

You can use the   and   buttons on the Virtual Topology context toolbar to cycle through virtual topology entities in the sequence in which they were created and display them in the Geometry window.

  1. In the Geometry window, select a virtual entity.

  2. On the Virtual Topology context toolbar, click  or  .

Remember the following information when using   and  :

  •   and   are grayed out until at least one virtual entity has been defined.

  • If no virtual entities are selected, clicking  displays the first virtual entity in the sequence and clicking   displays the last virtual entity in the sequence.

  • If the currently selected virtual entity is the last in the sequence, clicking  displays the first virtual entity in the sequence. If the currently selected virtual entity is the first in the sequence, clicking   displays the last virtual entity in the sequence.

  • If using   when multiple virtual entities are selected, the entity that has the highest ID (based on the order in which the entities were created) is considered to be the current selection, and clicking   displays the entity that follows it.

  • If using   when multiple virtual entities are selected, the entity that has the lowest ID (based on the order in which the entities were created) is considered to be the current selection, and clicking   displays the entity that precedes it.

  • If the current multiple selection contains no virtual entities,   and   work as though there are no selections (That is, clicking  displays the first virtual entity in the sequence and clicking   displays the last virtual entity in the sequence). If the current multiple selection contains a mixture of virtual entities and non-virtual entities, the non-virtual entities are ignored.

  • If a split is selected, both edges or all faces of the split are displayed.

  • If any virtual entities are deleted or merged, the sequence is adjusted automatically. For example, the following behaviors occur if you create 14 virtual entities and then perform these actions in order:

    1. If you select the fifth virtual entity and click  , the sixth virtual entity is displayed.

    2. Click  , and the fifth virtual entity is displayed.

    3. Delete the sixth virtual entity, select the fifth virtual entity, and click  . The seventh virtual entity is displayed. This occurs because the sixth virtual entity was deleted.

    4. Merge the seventh and eighth virtual entities, which creates a fifteenth virtual entity.

    5. Select the fifth virtual entity and click  . The ninth virtual entity is displayed. This occurs because the sixth virtual entity was deleted and the seventh and eighth were merged to form a new entity.

Deleting All Virtual Entities

You can use the Delete All Virtual Entities option to delete all virtual topology entities from a model at one time, regardless of type.

  1. Highlight the Virtual Topology object in the Tree Outline or select any virtual topology entity in the Geometry window.

  2. Right-click and select Delete All Virtual Entities.

  3. Answer Yes at the prompt.

Deleting All Virtual Cells

You can use the Delete All Virtual Cells option to delete all virtual topology cells (the virtual topology group itself, including any virtual split edges, virtual split faces, or virtual hard vertices, will not be deleted). This option is available only when the Virtual Topology object in the Tree Outline is highlighted and virtual cells, as well as virtual split edges, virtual split faces, and/or virtual hard vertices exist. Otherwise, use the Delete All Virtual Entities option.

  1. Highlight the Virtual Topology object in the Tree Outline.

  2. Right-click the Virtual Topology object in the Tree Outline or in the Geometry window. Select Delete All Virtual Cells.

  3. Click Yes at the prompt.

Deleting All Virtual Split Edges

You can use the Delete All Virtual Split Edges option to delete all virtual split edges (the virtual topology group itself, including any virtual cells, virtual split faces, or virtual hard vertices, will not be deleted). This option is available only when the Virtual Topology object in the Tree Outline is highlighted and virtual split edges, as well as virtual split faces and/or virtual hard vertices exist. Otherwise, use the Delete All Virtual Entities option.

  1. Highlight the Virtual Topology object in the Tree Outline.

  2. Right-click the Virtual Topology object in the Tree Outline, or in the Geometry window. Select Delete All Virtual Split Edges.

  3. Answer Yes at the prompt.

Deleting All Virtual Split Faces

You can use the Delete All Virtual Split Faces option to delete all virtual split faces (the virtual topology group itself, including any virtual cells, virtual split edges, or virtual hard vertices, will not be deleted). This option is available only when the Virtual Topology object in the Tree Outline is highlighted and virtual split faces, as well as virtual split edges and/or virtual hard vertices exist. Otherwise, use the Delete All Virtual Entities option.

  1. Highlight the Virtual Topology object in the Tree Outline.

  2. Right-click the Virtual Topology object in the Tree Outline, or in the Geometry window. Select Delete All Virtual Split Faces.

  3. Click Yes at the prompt.

Deleting All Virtual Hard Vertices

You can use the Delete All Virtual Hard Vertices option to delete all virtual hard vertices (the virtual topology group itself, including any virtual cells, virtual split faces, or virtual split edges, will not be deleted). This option is available only when the Virtual Topology object in the Tree Outline is highlighted and virtual hard vertices, as well as virtual split faces and/or virtual split edges exist. Otherwise, use the Delete All Virtual Entities option.

  1. Highlight the Virtual Topology object in the Tree Outline.

  2. Right-click the Virtual Topology object in the Tree Outline or in the Geometry window. Select Delete All Virtual Hard Vertices.

  3. Click Yes at the prompt.

Deleting Selected Virtual Entities

You can use the Delete Selected Virtual Entities (And Dependents) option to delete selected virtual topology entities, along with any dependents if applicable.

To use a right mouse button click:

  1. Highlight any object in the Tree Outline (for example, the Geometry or Mesh object).

  2. In the Geometry window, select the virtual entities that you want to delete.

  3. Right-click and select Delete Selected Virtual Entities (And Dependents).

  4. Answer Yes at the prompt.

To use the Virtual Topology context toolbar:

  1. Highlight the Virtual Topology object in the Tree Outline.

  2. In the Geometry window, select the virtual entities that you want to delete.

  3. Choose Delete on the Virtual Topology context toolbar.

  4. Click Yes at the prompt.

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