Method for Analyzing Surface Shapes

by Justin

May 28, 2015

Hey guys, need your help.

Problem: Need to determine which surfaces are rectangular and which are shaped (trapezoid, parallelogram etc.) within a 1/8" tolerance.

1. Some of these surfaces are non-planar which makes me believe I need to unroll the surfaces first before analyzing. The problem here, is that I haven't had any luck with unroll components orienting the surfaces correctly on the xy.

2. I also cant rely on only measuring angles between vectors (surface edges) because as panels are different sizes this will not give me an accurate reading of the overall shape. (if its a small panel with 91 degreee angle it will not effect the shape much, if its a large panel it could be much different.)

I'm not sure if there's a simple solution to this or not, but its got me stumped, any help would be great. Thanks guys!

  • up

    Jesse

    First get yourself a good unroll component, The one i used you can download here

    In this example I only tested two sides of the rectangle, if you want to test all four sides for your tolerance you just have to copy the X and Y test again and change the list items to the other two sides 2,3 and 3,0.Also here is the visual result:

    5

    May 28, 2015

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    • up

      peter fotiadis

      Hi Justin,

      Just spotted that one.

      Generally speaking this is extremely easy to do with code: see a 10 minutes work demo example (regarding Brep "classification" matters only).

      This could being vastly "expanded" by (a) including every test imaginable [like the max allowed "deviations on edge sizes" due to non 90 degrees angles blah, blah] or by (b) creating "layouts" in XY Plane for fabrication or ... whatever.

      PS: Load your file first (no internalized test data).

      best, Peter

      3

      May 29, 2015