Flip for closed polysurfaces

Flip does not work on closed polysurfaces.

The following sequence allows Flip to be used on a single closed polysurfaces.

Select the closed polysurface

If Explode is started before the closed polysurface is selected then the individual individual surfaces have to be selected after Explode.

Request: Flip works directly on closed polysurfaces.

Hi David -
I must be missing the bigger picture here …

If you run Explode without a preselection, the result will be deselected. This is by design.
If you have a bunch of individual surfaces that are pointing to the inside of a common bounding volume, joining these will flip the normals to the outside. This is by design.
The Flip command allows for multiple inputs.

It sounds like the simple answer to that sequence is to add SelLast before flipping.


The bigger picture has two parts:

  1. A method for flipping the normals of a closed polysurface in case someone is searching for one.

  2. A request that Flip work on closed polysurfaces.

The comment about needing to reselect the surfaces after running Explode without preselection was an observation, not a complaint.

Is there a reason why you need to do this though? You want to be able to have a closed polysurface with the normals facing inwards?

Reason for this is because closed polysurfaces with normals facing inward sometimes occur, such as in this thread. Boolean Union Failing - #4 by davidcockey The method above provides a simple way to flip the normals so they face outward.