Compare Parts on Update is a Geometry Import option, available inside Ansys Workbench. The Ansys Mechanical editor and Ansys Meshing make use of the benefits of the preference.
The option compares the existing geometry and updated-to geometry to determine if any bodies/parts remain unmodified. When you choose the Refresh Geometry context menu option (right-click the Geometry tree object or anywhere in the Geometry window), if no changes to the body are detected (found to be unmodified), then the body/part does not need to be remeshed after the update has occurred.
The option can be set or modified before any update in the Ansys Mechanical editor or Ansys Meshing and the subsequent updates will utilize that option.
For more information, see Compare Parts on Update in the Advanced Geometry Options table at Geometry Preferences in the CAD Integration section of the Ansys Help.
Note: The Non-Associative setting for Compare Parts on Update depends on the entities from the updated model being in the same order as the original model. If that order changes at any level, that part will be marked as modified. For most CAD systems if the CAD session remains open the order is more likely maintained then if the CAD is shut down and the model reopened. For those geometry imports that support associativity the associative option for Compare Parts on Update is the preferred mechanism.
The Compare Parts on Update feature is not supported for line bodies.
If the final existing instance of a part is modified such that it is no longer instanced, an associative Compare Parts on Update may result in both the un-modified and the modified part being marked as un-meshed, due to a change in the transformation matrix of the un-modified part.
Accessibility
From the Tools menu in Ansys Workbench, select Options to display a dialog box and then, select Geometry Import. The Advanced Options category includes the Compare Parts on Update option.
The choices are:
No (default): No post-update comparison will be attempted and all bodies/parts included in the update will be marked as dirty and needing remeshed.
Associatively: Searches through the part data to find appropriately matching entities for comparison based on their associative data. This option is slower because of that search but provides the best option if parts or bodies are reorganized or added to or deleted from. The Associatively option is the recommended comparison option and should be used exclusively if the model utilizes merged topology from the DesignModeler application.
Non-Associatively: Generates a faster comparison but only does comparison on entities of a corresponding index (body 1 original -> body 1 updated). If bodies are not reorganized or added to or deleted from this method should be adequate, as long as the original topology is preserved. You should not use the Non-Associatively option when using merged topology options (Automatic or Imprints) from the DesignModeler application.
The three options for Tolerance are:
Tight (default): the Tight setting identifies updates geometry with only very small deviations as unchanged.
Normal: the Normal setting allows a 100 times greater deviation than tight.
Loose: the Loose setting is 100 times greater than normal.
These deviations are intended to account for modest internal deviations that can sometimes be generated in computational values or in the mathematical representation of some geometry. It is not intended to hide true geometric modifications.