Flipping face normals - Improvement request


Currently, if I have a non-manifold surface "solid" and one face has incorrect orientation, I have to do the following to correct the orientation:


  1. Copy the face in place
  2. Delete the original face
  3. Correct the orientation
  4. Reinclude the new face in the non-manifold surface
  5. Mesh cleanup (dissociation problems, etc.)

Ideally, one could simply flip the face normal of a single face inside a non-manifold surface, with an automatic remesh. This could be a tool in the meshing toolbox.


Please don't tell me that the topology is impossible, because the surface normals have nothing to do with the definition of a non-closed joined surface. They can be random. And often are. That's the problem. The warning message that's currently given is bogus.


Re: Flipping face normals - Improvement request

Solution Partner Phenom Solution Partner Phenom
Solution Partner Phenom

Dear Kava,

Once you create a NonManifold sheet body then not possible to change the normal direction of a local surface that belongs to the sheet body, this is the current state of art. To avoid this problem I suggest -as an intermediate step- to use first command GEOMETRY > SOLID > STITCH to stitch all surfaces without any T-JUNCTIONS, the result will be a sheet body perfectly stitched and with all surface normal correctly oriented (all normals will have the same orientation). Finally, use command GEOMETRY > SURFACE > NonManifold-Add.

Best regards,

Blas Molero Hidalgo, Ingeniero Industrial, Director
WEB: http://www.iberisa.com
Blog Femap-NX Nastran: http://iberisa.wordpress.com/

Re: Flipping face normals - Improvement request

Siemens Phenom Siemens Phenom
Siemens Phenom

We just updated the Modify, Update, Surface Normal command for the next release of FEMAP.  The command now prompts for surfaces, once you pick, those connected to solid Solids are thrown out, those connected to sheet bodies, which must have consistent normals, reverse all the surfaces on that body.  Selected surfaces connected to Non-manifold (General bodies in Parasolid terms), are reversed, leaving non-selected ones on the same solid as they were.


This will be in FEMAP v11.4.



Re: Flipping face normals - Improvement request


Very nice! Good to know. Thank you.