Reverse Facet Normals

Source file: reverse-facet-normals.htm

3D programs need to keep track of which side of a facet that the normals are pointing. Some facets may be incorrectly formed when a model is built or modified, resulting in the normals being linked to the wrong side. Thus problems can occur when operating on facets or displaying surfaces.

Reverse facet normals allows you to manually flip the position of a wrongly pointing normal.

1. Select the facet that needs its normal reversed. All normals on a surface are drawn as lines extending from the centres of the facets.

2. On the Labs ribbon tab, go to the Edit group and select Reverse Facet Normals.

   

3. Select Display normals of selected facets to see a representation using lines emanating from the centres of the facets. The length of these representative lines can be adjusted using the slider for Normal length.

4. Click OK or Apply to run the task.

Note:  If you clicked Apply, close the tool with the Cancel button. If you click OK, the function will run again, returning the normals to their original orientations.

A tunnel surface where facet normals are supposed to point outwards, but one facet's normal points inwards, indicated by the arrow.