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ProFeature16-Pearl
16-Pearl
December 9, 2024
Question

What is Slope analysis

  • December 9, 2024
  • 1 reply
  • 1061 views

Hello all,

 

I came across Slope Analysis, and despite reading the whole Help page, I still do not understand what "Slope Analysis" is and what it is used for.

ProFeature_0-1733742210890.png

 

  1. What is the meaning of Min/Max slope (-1...1)?
  2. What are the units of the slope results?
  3. What does this analysis check?
  4. This analysis has the option to generate an Analysis Feature, which case uses an analysis feature for this analysis?

Thank you for the responses in advance.

1 reply

tbraxton
22-Sapphire II
tbraxton22-Sapphire II
22-Sapphire II
December 9, 2024

The slope in this context is the calculation of the derivative of a surface (function) at any arbitrary point on the surface. The slope is dimensionless (no units). It can be used in a variety of ways but one of interest is in the optimization of geometry using the behavioral modeling extension (BMX) in Creo. You can create a slope analysis feature and use this in an optimization study with BMX functionality.

    P
    ProFeature16-PearlAuthor
    16-Pearl
    December 10, 2024

    Hi @tbraxton 

     

    Your answer is incorrect at the start and overly general at the end.
    Do you have any experience with this analysis?

    tbraxton
    22-Sapphire II
    tbraxton22-Sapphire II
    22-Sapphire II
    December 10, 2024

    @ProFeature , I did not write the code for this analysis tool so there is certainly one or more people who know more about how it works than I do. If you know that something I have stated here is not accurate, please elaborate. I described it conceptually in Calculus terms as this is likely something that many community members will remember from their studies.

     

    What I believe is used for this tool is a comparison of unit normal vectors relative to each other to quantify a difference between them which is used to derive the value for slope. I suspect that the vector dot product of these unit vectors is used to derive the cosine of an angle to produce the slope value that is reported. This is pure speculation on my part. If you need specific details on the algorithm used, consult PTC support.

     

    I have made a trivial test case to confirm that this assumption on my part is accurate, and this would lend credibility to that assumption. This is a planar surface made at a 45-degree angle relative to DTM 2. This surface is normal to DTM3 as well (the normal vectors are coplanar in this case). When a slope analysis is run, the result reports that the slope at all points on the surface is 0.707. The cosine of 45 degrees is 0.707.  You can try other angles and see the cosine function appears to work across the range of 0-90 degrees for this trivial test case.

     

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    tbraxton_4-1733848927097.png

     

     

     

     

     

     

     

     

     

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