Part Comparison in CATIA V5

January 17, 2020 Amy Rath

In CATIA V5, you can compare the same part from two different development stages to see how the design has matured over time.  Generally a comparison is performed on the part when it was early planning to the same part that was released into mass production. We will compare the two parts shown in Figure 1-1. In the picture below; the left side part is considered the old and the right side part is considered the new.

FIgure 1-1
Figure 1-1
 

Part comparison function is in the DMU Space Analysis workbench. The SPA license may need to be selected in order to receive this workbench. You can find the compare icon in the DMU Space Analysis toolbar as shown in Figure 1-2.
Figure 1-2
Figure 1-2

 

In order to perform a part compare both parts need to be added into a product file as shown in Figure 1-3. CouplingBase is the old, and CouplingBase2 is the new. Currently the parts are overlaid.
FIgure 1-3
Figure 1-3

Select the Part Compare icon Compare icon

Here is an example of the dialog box as shown in Figure 1-4.
Figure 1-4
Figure 1-4

 

First, select the Old version, then select the new version from the product file. An example is shown in Figure 1-5.
FIgure 1-5
Figure 1-5

 

There are two different options for comparing parts; Geometric and Visual comparison.

Visual comparison:

  • Visually represents the difference between the models
  • More accurate
    • Yellow material: What’s shared between the two models
    • Red material: What’s in the new but not in the old
    • Green material: What’s in the old but not in the new
  • Doesn’t allow the comparison to be saved
  • Accuracy can be adjusted

Figure 1-6
Figure 1-6

 

Here, our models are being compared using visual comparison as shown in Figure 1-7. The red material is geometry that has been added since the old model. The green is representing what was on the old but was removed from the new model. Yellow is showing what is shared between the two models. 
Figure 1-7
Figure 1-7
 

Geometric Comparison:

  • Compares models by creating geometrical shapes
  • The more accurate you make the comparison the better the results, however, it is not as accurate as visual comparison
  • Can be saved as an external file

Figure 1-8
Figure 1-8
 

Here, our models are being compared using geometric comparison as shown in Figure 1-9. The red material is geometry that has been added since the old model. The green is representing what was on the old but was removed from the new model. You can see the geometrical shapes representing what has been changed. CATIA does open an additional window as shown in Figure 1-9 to show the comparison.
Figure 1-9
Figure 1-9

 

The accuracy can be adjusted for geometrical comparison making it more accurate. This means that CATIA will compare the difference by making smaller geometrical shapes. The more accurate you go, the more time the analysis takes to run.

 

Here is an example of changing the geometrical comparison to 0.1mm accuracy. It did take longer to preview the results. The results are shown in Figure 1-10. The results are more accurate with smaller shapes.
Figure 1-10Figure 1-10
 

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More information about this topic can be found in the Rand 3D training class, DMU Navigator and Space Analysis.

About the Author

Amy Rath

Technical Training Engineer<br><br>As a resident instructor at a large automotive OEM, Amy instructs CATIA classes and develops customer-specific course material that includes training videos and interactive training techniques. Amy’s areas of expertise include CATIA V5 Human Modeling, Functional Tolerancing and Annotation, VPM Navigator and Generative Drafting to name a few. Amy is a Dassault Systèmes Certified instructor for CATIA V5 Part and Assembly at the Expert level.

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