Weird render mesh on simple shape

Rhino Rhino for Windows
1

Steps to reproduce:

  1. _Sphere 0 10 _Enter
  2. Create a line in front view at Z=8
  3. trim top of sphere with line
  4. create line at Y=0 in top view
  5. use both lines to split trimmed sphere in 4 parts
  6. switch on shaded in perspective view

Pasted image829×378 79.8 KB

weird_rendermesh.3dm (227.9 KB)

I’m on RH5/SR12

2

@menno 32Bit looks ok.

_Sphere 0 10 _Enter
_Trim _Pause _Pause _Enter
_Split _Pause _Pause _Enter
_ExtractRenderMesh _Pause _Enter
_SelSrf _Enter
_Hide _Enter

3

Hi Menno,

Don’t see that here… Do you have some custom mesh settings in that file or something? --Mitch

4

The mesh settings are “Jagged & Faster” - I used Ctrl+N, Alt+M (New File, No Template) to start the file.

5

I’m also seeing it, but the distortion comes and goes as I rotate the object.

6

Shrinking the surface tunes it up - - still poking…
I cannot make a new surface so far that shows this, though I see it in yours.
-Pascal

7

Looks like it has something to do with the surface being trimmed. I tried ShrinkTrimmedSrfToEdge and the problem went away. Also went away when the surfaces were untrimmed.
weird_rendermesh_DC.3dm (1.4 MB)

8

Sure, I could also change the mesh settings and get a good mesh. I just wanted to point out that this is unexpected behaviour - call it a bug if you want.