Merge Entities
Use the Merge Entities () operation to merge entities of a 3D mesh, as shown in Figure 8-58. It is possible to merge boundaries, edges, and points by specifying entities to keep and the entities to remove. Depending on the specified tolerance, only parts of the entities are merged, similar to the geometry operation Collapse Face Regions.
Figure 8-58: Merging two boundaries of two disconnected components in a mesh by specifying the boundary to keep (yellow) and the one to remove (magenta). The image to the right shows the result after the faces have been merged.
This operation is supported in 3D models only.
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If the mesh is conforming to a geometry, consider using Remove Details or any of the Virtual Geometry Operations to remove entities or to collapse narrow face regions already in the geometry.
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For a more automated operation to collapse small entities of a mesh, use Collapse Entities.
To merge entities in a mesh, select one or several edges or boundaries in the Graphics window, then:
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Right-click in the Graphics window, and select Merge Entities from the Cleanup and Repair menu. For more information, see The Graphics Context Menu.
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In the Mesh toolbar, choose Merge Entities from the Cleanup and Repair menu ().
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Right-click the Mesh node and choose Merge Entities from the Cleanup and Repair menu.
Enter the properties for the Merge Entities node using the following sections:
Type of Selection
Select the dimension of the entities to merge using the Geometric entity level setting. The options are Boundary (default), Edge, and Point.
Use the option Pairing of entities to keep and remove to choose how to pair the entities to merge. Select Automatic (default) to enter all entities in the Geometric Entity Selection and let the operation choose which entities to keep and which entities to remove. Select Manual to enter the entities to keep and remove in the Entities to Keep and Entities to Remove, respectively.
You can inspect the automatically chosen entities to keep and remove by first building the operation with the Automatic setting and then switching to Manual.
Geometric Entity Selection
This section is visible if the option Pairing of entities to keep and remove is set to Automatic.
Click the Active button to toggle between turning ON and OFF selections. Select all the entities to merge, for example by clicking in the Graphics window.
Entities to Keep
This section is visible if the option Pairing of entities to keep and remove is set to Manual.
Click the Active button to toggle between turning ON and OFF selections. Select the entities to keep, for example by clicking in the Graphics window.
Click the Swap Entities to Keep and Remove button () to swap the entities in the selection to keep above and the entities in the selection to remove below.
Entities to Remove
This section is visible if the option Pairing of entities to keep and remove is set to Manual.
Click the Active button to toggle between turning ON and OFF selections. Select the entities to remove, for example by clicking in the Graphics window.
Merge
Use the Maximum distance setting to control the maximum distance to bridge when merging entities of the mesh, as shown in Figure 8-59.
Figure 8-59: Merging two edges using different Maximum distance values. A larger value of the Maximum distance collapses a larger portion of the narrow face region.
Choose Relative to enter a value in the Relative distance field. This value is relative to the length of the longest side of the mesh’s bounding box. Select Absolute to specify a value in the Absolute distance field. When the operation is built with the setting Automatic (the default), the value in the Absolute distance field is automatically updated to correspond to the actually used distance. The automatic tolerance is based on the size of the bounding box of the mesh.
Use the Placement of mesh vertices setting to specify if the mesh vertices of the entities to be removed will be placed on the Curved (default) or Linear representation of the entities to keep, as shown in Figure 8-60.
Figure 8-60: The mesh vertices of the boundary to remove is placed on the edge of the boundary to keep in either a curved representation (upper right) or a linear representation (lower right).
Use the Deformation propagation edit field (or slider) to determine how much of the deformation on the remove side is propagated further into the side to remove. A low value will only move the mesh vertices closest to the entity to remove while a high value will shift the whole connected component toward the keep side.
Entity Matching
Use the Method setting to specify the way to match a determined pair of entities to keep and remove. The method Make imprints means that the keep entities make an imprint on the remove entities and, symmetrically, the remove entities make an imprint on the keep entities. Then, only the overlapping imprints are merged.
Use the Precision edit field or slider to specify the accuracy of the imprint. A low precision will give a sloppier matching, meaning that regions of entities with approximately the same shape will be matched without imprinting, while high precision gives a more accurate imprint but also means that small entities and details can appear.
The method One-to-one forces the entities on the remove side to be matched with the keep side without any imprints. This is useful when the shape is approximately the same and you want to match them exactly. Note that if the entities have too different shape, the merge will generally not be successful with this option.
Collapse Entities