Comparing Assemblies
In addition to comparing the geometry of two parts, the Compare tool can also compare the structure and geometries of two assemblies.
To Compare Two Assemblies
1. Click > . The Compare Settings dialog box opens.
2. Select
First Item and in the structure tree or the view, select the first assembly. Then select
Second Item and select another assembly.
3. To switch the two selected items, select
.
4. To align the coordinate systems of the assemblies, select Align default CSYS.
| If you want to compare centers of gravity, make sure this check box is not selected. |
5. To compare the sub-structures of the assemblies and identify any components that have been added, modified, or removed, select Compare Sub Structures. The Child Matching Attributes table is displayed.
6. When comparing sub structures, in order to match children in one assembly to children in the second assembly, you need to specify what attribute(s) to use as the children’s identifier. For example, if you specify the Display Name attribute, the Compare tool will match every child of the first assembly with a child in the second assembly that has the same Display Name. If no single attribute identifies the children uniquely, you can choose a combination of attributes.
To specify child matching attributes:
a. Select Add Attributes.
b. On the Insert Attributes, double-click the desired attribute, or select it and then select Insert Name. Repeat for every attribute you wish to specify.
c. Select Close.
7. In the Resolve Conflicts drop-down list, choose how to deal with cases in which a child in one assembly is matched to more than one child in the other assembly according to the selected attributes. The options are as follows:
◦ None: Do not resolve any conflicts.
◦ By Order: Match the children according to their order.
◦ By Relative Position: Match the children according to their relative position to the parents.
8. The Compare tool can perform a detailed geometric comparison of the children of the assemblies. For children that are found to be modified, this functionality enables you to see which features were added or removed and which are common to both versions of the child (see Common, Added, and Removed buttons below).
To control when geometric comparison is generated, select one of the options in the Geometric Comparison drop-down list:
◦ Always: Always generate the geometric comparison in the viewer area (slowest option).
◦ As Required: Generate the geometric comparison in the viewer area only when the COG, Volume, and Surface Area values are different.
◦ Never: Determine whether the child has been modified but do not generate any further geometric comparison (fastest option).
| If you select Never, to Compare tool will not generate the Common, Added, and Removed displays for pairs of components with the status “Modified”. |
9. Select Compare. The system performs the comparison and displays the results in a message box. The detailed result tree appears in the Compare tab in the secondary panel.
Viewing the Results in the Compare Tab
The detailed results appear in the Compare tab in the secondary panel. Each row contains the name of the component in the first assembly, the result of the comparison (Status), and the name of the respective component in the second assembly.
The possible statuses are:
• Identical: The components are the same in geometry and in their relative position to the parent.
• New: The component is not present in the first assembly but present in the second.
• Deleted: The component is present in the first assembly but not present in the second.
• Moved: The relative location of the components (Position, Rotation, or Scale) is different.
• Modified: The geometry of the components is different.
• Changed: For components that contain further child components – at least one of the children is not identical.
• Unknown: The mass properties for the pair are unavailable and Geometric Comparison has been set to Never.
Select a component pair in the Compare tab to see the detailed comparison of the components’ parameters in the lower data panel and the graphics area.
The parameters are as follows:
• Position (Parent): The position of the part relative to its own parent
• Rotation (Parent): The orientation of the part relative to its own parent
• Scale (Parent): The scale of the part relative to its own parent
• Volume: The volume value for each part in the pair in the view.
• Center of Gravity: The Center of Gravity for each part in the pair in the view.
• Surface Area: The surface area for each part in the pair in the view.
• Volume (Origin): The volume of the original shape of the part.
• Center of Gravity (Origin): The Center of Gravity of the original shape of the part.
• Surface Area (Origin): The surface area of the original shape of the part.
• Geometry (Volumes): Whether the parts have the same geometry in the view in the same location.
To zoom in on a pair in the view or to show only one pair, right-click the chosen pair and select Zoom Selected or Isolate Selected, respectively.
To reopen the Compare Settings dialog box, select > .
Filtering the Results
To filter the pairs that are displayed in the Structure, in the Compare tree and in the lower data panel, select the appropriate button in the Structure Display group in the Geometry Compare tab:
• 
Identical: Show/hide identical pairs.
• 
New: Show/hide components that were added to the second assembly.
• 
Deleted: Show/hide components that were deleted from the second assembly.
• 
Moved Part: Show/hide pairs in which a part was moved.
• 
Moved Assembly: Show/hide pairs in which an assembly was moved.
| • The colored strip at the bottom of the button indicates the color in which the components will be displayed. • To change the color and opacity of the components, select the down arrow under the filtering button. |
When you select a pair for which the status is Modified (or when you select the parent of such a pair), the Geometry Compare tab also shows a Geometry Compare Display group. Use the buttons in this group as follows:
• First Item: Show/hide the first item in the pair.
• Second Item: Show/hide the second item in the pair.
• 
Common: Show/hide the common features of the components.
• 
Added: Show/hide the features that were added in the second component.
• 
Removed: Show/hide the features that were removed in the second component.
| • The colored strip at the bottom of the button indicates the color in which the items or features will be displayed. • To change the color and opacity of the items or features, select the down arrow under the filtering button. |
Saving the Results
1. Select
Save Report.
2. In the Save Compare Report dialog box, type a name for the report and select OK.
The comparison settings and results are stored as a report in the Compare pane of the primary navigation panel.
| When connected to Windchill, the Compare Report is saved as an annotation. Use the bottom right pane to choose which object to save the annotation with. |
Compare. The Compare Settings dialog box opens.