More trim issues

Yes, yes there’s a singularity here, but it’s an imported STEP file that I need to clean up and I can’t really change that…

  1. Why does trimming the right part of the black surface with the green one fail?
  2. Why doesn’t the intersect curve (red) extend to the entire surface?

Btw, ignore the unit tolerances for this file… I’ve been playing with changing it to see if it makes a difference and so far it has not…

intersect-fail.3dm (65.8 KB)

[spoiler]Had to jump softwares to get this done…

model1.stp (12.1 KB)

Another example (the joining surface to the previous one)…


trim2.3dm (73.8 KB)


model2.stp (12.6 KB)

I see this, thanks.
RH-71436 SSX failure example


1 Like

Both examples fail where knot isocurves are coincident with the intersecting surface.

To obtain curves for trimming, you can use rhinopython/ at master · CADacombs/rhinopython · GitHub

It works as so:

  1. Determines a starting curve.
  2. Pulls the curve from # 1 to two faces or surfaces.
  3. Creates a tween curve from the results of # 2.
  4. Pulls the result of # 3 to both faces or surfaces.
  5. Repeats # 3 and # 4 until the deviation of the two latest results are below a certain threshold.