Clash Results Consistency

This section provides information about clash result consistency problems

Why are some clashes not calculated?
Why do users obtain extra clashes?
How to ensure clash results consistency? 

Why are some clashes not calculated?

You notice missing clashes after clash computation. Four main reasons can explain this result:

  • SpI did not find any database impacts for the modifications performed by the user.

  1. Refer to Step 3: Customizing SpI Settings.

  2. Read carefully Spatial Index FAQ section to find a solution.

  • There is no clash-rule defined to calculate these expected clashes by the user.

  1. Check clash rules consistency and syntax,

  2. Edit your clash rule and/or

  3. Add a new rule if needed.

    For more information, read Knowledgeware Rule-based Clash in Space Analysis User's Guide

  • SpE points a wrong clash rule file.

  1. Check the CATProduct, if this does not solve the problem, then,

  2. Check the SpE Server variable is correctly set:



  3. Check the CATIA parameters are correctly set in Tools-> Options...

    Refer to Customizing section

Why do users obtain extra clashes?

  1. Check the clash rule syntax.

  2. Check your clash rule in terms of contents.

    Read Knowledgeware Clash Rules

How to ensure clash results consistency?

  1. Check Clash rule syntax:



    DefineInterferenceComputation(p1:Product, p2:Product, TypCalc: String, ClearVal: Length, NameShape1: String, NameShape2: String, ThisRule: KWERule)

    Defines the interference type, clearance value and shapes to be used in the interference computation between a pair of products.

    where TypCalc is the interference type and ClearVal the clearance value in MKS units. 


    if (p1 != p2) 
      DefineInterferenceComputation (p1, p2, 
                                                              "Clearance", 70mm,
                                                              "WRAPPING", "Shape 1",


    Make sure the  Knowledge Settings are correctly set either select the specific package needed:
    • SpaITFCheckMethod package must be be loaded (Tools -> Options... -> Parameters and Measure -> Language tab) or
    •  Select All packages option.
    Refer to Space Analysis Functions in Knowledge Expert

    For more information, see Space Analysis (Interference Checking) under Functions Packages in the Reference Information section of the Knowledge Expert User's Guide.

  2. Check your clash rule in terms of contents

    Read Knowledgeware Clash Rules

  3. Check the settings are correctly set in Tools > Options... 

    Make sure, the clash settings are identical on both server and client sides. This also applies to the rule-based clash defined as the client and servers must point to the same rule-based clash.

    For more detailed information refer to Customizing section.

  4. Make sure the 3D Accuracy setting located in  Performances tab page of General-> Display category is correctly set.

    The 3D accuracy must be identical both on server and client sides.