To Fix Flipped Triangles

Attempts to orient all triangles belonging to common shells by their normals

Fixing flipped triangles is important when repairing parts with an invalid orientation. The Status tab in the context area indicates whether the mesh is oriented properly. The number of triangles with an inverted orientation is reported on the Actions tab. By default, the outside surface of a triangle is blue and the inside is red.

The repair action Fix Flipped Triangles sums, for each shell, the areas formed by triangles with opposing normal directions, and will flip those triangles comprising the smaller of the two areas so that now all the triangles of a shell point either away from or towards the enclosed shell volume.

Flipped triangles are easily recognized with the red inner surface ("back face") visible on the outside of the part.

1. If not already opened, click Prepare > Repair Part to enter the repair module.
2. In the context view, switch to the Actions tab.
3. Click Fix Flipped Triangles.
   Tip: You can also access this command in the Repair menu, or right-click in the display and choose Fix Flipped Triangles.

Warning: If the part is not orientable, a dialog appears asking to attempt to fix the part. Be aware, this process does not always work and has the potential to destroy the mesh. Therefore, we recommend you apply the repair operation and reopen the repair module before clicking Yes to try and fix the part. Common causes of non-orientable surfaces are self-intersections and stitched triangles with opposing normals.