Using Model Reimport

The Model Reimport tool allows you to replace an imported assembly with a modified version of that assembly and re-execute the feature tree. When the tool is unable to map between original and updated bodies and faces, you are provided with a split window scene in which you can manually provide the mapping.

Model Reimport provides you with a workflow that is tailored to design optimization. For example, if an analysis was performed on an assembly, you can re-execute the same analysis on a modified version of the assembly, even when parts are added, removed, or modified.
Model Reimport assumes that you imported the original assembly directly into 3D-CAD and therefore have an ImportCad feature node in the feature tree. For instructions on importing geometry directly into 3D-CAD, see Importing Geometry into a 3D-CAD Model.

After importing the CAD assembly, you typically use 3D-CAD features to prepare the model for simulation. For example, you might use repair tools to clean the geometry and remove unnecessary details.

Suppose that after running a simulation on geometry built with the original assembly, you then receive an updated version with the same assembly. To avoid building the 3D-CAD feature tree again, you can use the Model Reimport action on the ImportCad node to read in the updated assembly. Some follow-up actions are necessary in order to match bodies and faces in cases where 3D-CAD cannot do so automatically. In addition, you must:
  • Identify any new geometry in the updated assembly that you wish to bring into the simulation
  • Decide what 3D-CAD does with any geometry in the previous assembly. You can either retain the previous geometry or delete it.

To use Model Reimport on an existing 3D-CAD feature tree:

  1. Right-click the Features > ImportCad node (or its renamed version) and select Model Reimport.
  2. In the Open dialog, select the modified CAD assembly file.
    3D-CAD reads the CAD assembly file and organizes its content into the following categories:
    Referred Modified Bodies
    Contains bodies that were modified, added, or deleted in the new assembly, and for which your input is required in order to successfully complete the reimport process. Two tables can appear in this section of the panel—Non-matching Bodies and Matching Bodies.
    1. Non-matching bodies — the left column (Old Bodies) shows bodies that existed in the original assembly but which 3D-CAD cannot identify in the new assembly. The right column (New Bodies) shows bodies that are in the updated assembly but which 3D-CAD cannot identify in the original assembly.
    2. Matching Bodies—this table contains pairs of bodies that 3D-CAD has successfully matched, but for which you must match old and new faces that 3D-CAD could not match.


    Modified Bodies
    Displays bodies that Model Reimport has matched. This is a read-only panel and you can visualise the original and modified bodies in the 3D-CAD View Scene.
    Transformed Bodies
    Contains bodies that have been transformed in the updated assembly.
    Unchanged Bodies
    Contains all bodies that are unchanged in the updated assembly.


  3. To match old and new bodies that the re-import failed to match, click through the list of pairs shown in the Non-matching Bodies list within the Referred Modified Bodies panel and complete the following actions:


    1. Click the mouse pointer on the left or right cell in the row.
    2. If the row has a named body in the left cell, and "Select body in scene" in the right cell, move the mouse pointer over to the bottom-right panel of the graphics window and look for a corresponding body.
      • If a corresponding body exists, select the body in the bottom-right panel. Then, from the buttons beneath the Non-matching Bodies list, click Match.
      • If no corresponding body exists, and you want to retain the Old Body in the updated assembly, click Add.
      • If no corresponding body exists and you want to remove the Old Body from the updated assembly, click Delete.
    3. If the row has "Select body in scene" in the left cell, and a named body in the right cell, move the mouse pointer over to the top-right panel of the graphic window and look for a corresponding body. Complete the action as in the previous step—that is, Match, Add, or Delete.
    4. If, after making a match, you want to do something different, you can right-click the row in the list and select Remove. The cells show their original contents before you made the match.

By default, the Show All Non-matching bodies check box is activated to display all non-matching bodies from both assemblies.

For some body pairs, the re-import process correctly matches the old and new bodies, but requires confirmation that the mapping between faces is correct. In this case, the Referred Modified Bodies panel contains a further list called Matching Bodies for which you must confirm the face mapping.

  1. To confirm face mapping for body pairs in the Matching Bodies list, for each row in the list do the following:
    1. Click the row ([1] in the diagram below).
      The graphics window updates to show the old and new bodies in their respective panels.
    2. Click Match Faces ([2] in the diagram below).
      The faces belonging to each body are shown in the Matching Faces tables.
    3. For each row in the Matching Faces table, click the row and complete the following actions (all part of [3] in the diagram below):
      • If the faces are not clearly shown in the graphics window, double-click the row in the Matching Faces list. The scene updates with a focus on the selected faces.
      • If the face match is incorrect, select the correct face from the bottom-right panel.
    4. When all faces are matching correctly, click Replace Body ([4] in the diagram below).


Possible Matching Faces

In some scenarios, the preceding process is not possible because 3D-CAD finds multiple possible matches between the faces of old and new bodies. These type of faces are shown in a table called Possible Matching Faces. The following screenshot shows an example where Model Reimport finds one original face that seems to match two new faces.

  1. To resolve this conflict shown in the Possible matching faces list:
    1. Click each row in turn and, in the graphics window, inspect the possible match.
    2. After reviewing the possible matches, select each of the incorrect matches in turn and click Delete. Retain the single match that is correct.


Non-matching Faces

In some cases, Model Reimport matches an old body and new body pair correctly, but cannot find matches for all the faces. In this scenario, the Referred Modified Bodies panel contains another list called Non-matching faces.

  1. To resolve the issues listed in the Non-matching Faces tables:
    1. Click a row in the table. The graphics window updates to highlight the face for which a match is required.
    2. In the graphics window, if you can see a matching face on the new body, select the face in the graphics window. The table row updates to show the name of the new face.
    3. If there is no new face that matches the old face then, in the Non-matching Faces list, deactivate the Has Matching Face check box for that row.
    4. After reviewing and correcting all entries, click Replace Body.

When you have correctly resolved all body and face matches, the Referred Modified Bodies panel becomes empty and the OK button at the bottom of the Model Reimport dialog becomes active.

  1. To complete the Model Reimport process, click OK.
After re-importing the CAD assembly, 3D-CAD executes the feature tree using the updated assembly of bodies and faces. If a feature can no longer be executed correctly due to a referenced body or face not being present, 3D-CAD marks the feature with an exclamation symbol.