Surface Trimming Problems

A surface that i created changes shape (flattens) after it has been trimmed? - Please advise on how i can avoid this

The surface was created by:

  • surface from network curves
  • flow along surface (at this stage i get the results i need)
  • trim (it is at this stage the surface distorts, flattens)!

Keen to hear your thoughts
Apologies I can’t upload the Rhino6 file as it is 36meg
Trimed Surface UN-trimed Surface

Hello - no need to send the entire file, it is generally easier all around if you export only the objects you are asking about and send that.


Hi Pascal,
Thanks so much for your prompt reply, but this is exactly what i did and unfortunately its still over 20meg.
i tried Save Small 25meg and Zip but still 22meg. Please advise,

Just the surface and the thing you are trimming with, exported to a new file, is 20MB, SaveSmall? Blimey. You can upload to, to my attention, and please include a link back here in your comments.


Hi Pascal,

Did you receive the download? - Please advise,

Hello- please set a custom render mesh, with a max distance edge to surface of 1 mm.

More info here:


Hi Pascal,
Does this infer that i need to convert the surface to Mesh before trimming?
Thanks kindly,

Hi Nic - it does not - it only means that the display mesh for the shaded surface needs to be made finer/more accurate.


Thanks Pascal - i give that a whirl