Difference in knot vectors of Patch command and Brep.CreatePatch method

Hello everyone!

I got a question on the Patch command in Rhino and the Brep.CreatePatch method in Rhino Common API. Please find the attached files patch_question.3dm and patch_question.gh.

  1. Same four curves are used in the two cases.
  2. Settings for Patch command are below.
  3. The parameters of Brep.CreatePatch method are below.
  4. Basically, I’m trying to get the same surface in Grasshopper as that in Rhino.

However, the knot vectors are different, with one ranging from 0 to 1 and the other having large ranges (see two panels). My questions are

  1. why the two method gives so different knot vectors?
  2. how can correctly make the surface created by Brep.CreatePatch method have large-ranged knot vectors?

Any help greatly appreciate!
patch_question.3dm (98.3 KB)
patch_question.gh (11.0 KB)