Surface deforms after trim

Rhino Rhino for Windows
,
1

Hi folks,
I’ve been trying out using T-Splines to convert meshed geometry (created with Grasshopper & Weaverbird) back to a NURBS polysurface. It seems to work well, however when I try and trim the resulting polysurface, it appears deformed afterwards - looks kind of blocky, as if it no longer has smooth continuity.
Does anyone know why this would happen? Any workaround perhaps?

BEFORE TRIM:

surface before.jpg1014×497 536 KB

AFTER TRIM:

surface after.jpg1014×497 503 KB

2

Help?

3

i assume its the display mesh which got tempered, using custom mesh might fix this. either this or it somehow switched on FlatShade which can be turned off with the exact same command.

4

Hi Ronan - to follow up on Richard’s comment - see
https://wiki.mcneel.com/rhino/meshfaq

-Pascal

5

Thanks Richard & Pascal.

I tried playing with the Custom Mesh settings and that seems to fix the problem!

So am I right in thinking that the NURBS geometry itself is fine, and the issue was purely to do with Rhino’s display of that geometry?

6

Yes, that is how it looks to me.

-Pascal